#inputvalidation — Public Fediverse posts
Live and recent posts from across the Fediverse tagged #inputvalidation, aggregated by home.social.
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API Security 101: Understanding the Foundation and Why Attacks are Rising
This article discusses the growing importance of API security and the rising number of attacks against APIs. The author explains that APIs have become critical components in modern applications, handling a wide range of tasks including authentication, data transfer, and business logic. However, their increasing usage has exposed numerous vulnerabilities. One specific example provided is an XSS (Cross-Site Scripting) attack on an API endpoint via client-side manipulation of cookies or JavaScript. The researcher was able to exploit insufficient input validation by injecting malicious scripts within the user's session cookie, which executed upon subsequent API requests due to the lack of Content Security Policy headers. The impact includes unauthorized access, data theft, and account hijacking. The author recommends implementing proper access controls, token-based authentication, rate limiting, and input validation to secure APIs. Key lesson: Secure APIs are crucial for maintaining application security in the modern digital landscape. #API #Cybersecurity #WebSecurity #XSS #Authentication #InputValidation -
This CVE Has Only 5 Reports on HackerOne — But a 94% Chance of Being Exploited Right Now
This vulnerability is an XSS (Cross-Site Scripting) issue with a high likelihood (94%) of immediate exploitation. The flaw stems from the application's insufficient input validation, specifically for user comments containing JavaScript code. Upon successful injection, these scripts execute in the context of the target domain due to lacking Content Security Policy headers, demonstrating a logical error in the application's handling of user inputs. The impact includes session hijacking, unauthorized access, or information disclosure. This CVE has only 5 reports on HackerOne, but it poses a significant threat due to its high exploitability. The researcher received $100 for their report; the program responded by implementing Content Security Policy headers to prevent future XSS attacks. To remediate similar issues, developers should validate user inputs at all levels and enforce proper CSP headers. Key lesson: Validate user input and implement Content Security Policies to protect against XSS attacks. #BugBounty #WebSecurity #XSS #InputValidation #ContentSecurityPolicy -
This CVE Has Only 5 Reports on HackerOne — But a 94% Chance of Being Exploited Right Now
This vulnerability is an XSS (Cross-Site Scripting) issue with a high likelihood (94%) of immediate exploitation. The flaw stems from the application's insufficient input validation, specifically for user comments containing JavaScript code. Upon successful injection, these scripts execute in the context of the target domain due to lacking Content Security Policy headers, demonstrating a logical error in the application's handling of user inputs. The impact includes session hijacking, unauthorized access, or information disclosure. This CVE has only 5 reports on HackerOne, but it poses a significant threat due to its high exploitability. The researcher received $100 for their report; the program responded by implementing Content Security Policy headers to prevent future XSS attacks. To remediate similar issues, developers should validate user inputs at all levels and enforce proper CSP headers. Key lesson: Validate user input and implement Content Security Policies to protect against XSS attacks. #BugBounty #WebSecurity #XSS #InputValidation #ContentSecurityPolicy -
API Security 101: Understanding the Foundation and Why Attacks are Rising
This article discusses the growing importance of API security and the rising number of attacks against APIs. The author explains that APIs have become critical components in modern applications, handling a wide range of tasks including authentication, data transfer, and business logic. However, their increasing usage has exposed numerous vulnerabilities. One specific example provided is an XSS (Cross-Site Scripting) attack on an API endpoint via client-side manipulation of cookies or JavaScript. The researcher was able to exploit insufficient input validation by injecting malicious scripts within the user's session cookie, which executed upon subsequent API requests due to the lack of Content Security Policy headers. The impact includes unauthorized access, data theft, and account hijacking. The author recommends implementing proper access controls, token-based authentication, rate limiting, and input validation to secure APIs. Key lesson: Secure APIs are crucial for maintaining application security in the modern digital landscape. #API #Cybersecurity #WebSecurity #XSS #Authentication #InputValidation -
🌟 Oh no, another CVE just dropped! 🙄 It's a good thing we have an endless supply of version numbers and cryptic abbreviations to keep us entertained while the "experts" scramble to patch their precious AI toys. 🤖 Just sit back and watch as the "critical severity" takes a leisurely stroll through insecure headers, because who needs proper input validation in 2026 anyway? 😂
https://badhost.org/ #CVE2026 #AIsecurity #inputvalidation #cybersecurity #vulnerabilities #HackerNews #ngated -
🌟 Oh no, another CVE just dropped! 🙄 It's a good thing we have an endless supply of version numbers and cryptic abbreviations to keep us entertained while the "experts" scramble to patch their precious AI toys. 🤖 Just sit back and watch as the "critical severity" takes a leisurely stroll through insecure headers, because who needs proper input validation in 2026 anyway? 😂
https://badhost.org/ #CVE2026 #AIsecurity #inputvalidation #cybersecurity #vulnerabilities #HackerNews #ngated -
🌟 Oh no, another CVE just dropped! 🙄 It's a good thing we have an endless supply of version numbers and cryptic abbreviations to keep us entertained while the "experts" scramble to patch their precious AI toys. 🤖 Just sit back and watch as the "critical severity" takes a leisurely stroll through insecure headers, because who needs proper input validation in 2026 anyway? 😂
https://badhost.org/ #CVE2026 #AIsecurity #inputvalidation #cybersecurity #vulnerabilities #HackerNews #ngated -
🌟 Oh no, another CVE just dropped! 🙄 It's a good thing we have an endless supply of version numbers and cryptic abbreviations to keep us entertained while the "experts" scramble to patch their precious AI toys. 🤖 Just sit back and watch as the "critical severity" takes a leisurely stroll through insecure headers, because who needs proper input validation in 2026 anyway? 😂
https://badhost.org/ #CVE2026 #AIsecurity #inputvalidation #cybersecurity #vulnerabilities #HackerNews #ngated -
🌟 Oh no, another CVE just dropped! 🙄 It's a good thing we have an endless supply of version numbers and cryptic abbreviations to keep us entertained while the "experts" scramble to patch their precious AI toys. 🤖 Just sit back and watch as the "critical severity" takes a leisurely stroll through insecure headers, because who needs proper input validation in 2026 anyway? 😂
https://badhost.org/ #CVE2026 #AIsecurity #inputvalidation #cybersecurity #vulnerabilities #HackerNews #ngated -
How I Found a P1 Bug in a Bug Bounty Program (Step-by-Step Guide)
This article details the discovery of an XSS vulnerability due to insufficient input validation and lack of Content Security Policy (CSP). The application accepted user input for a query parameter without proper sanitization, allowing script injection through the 'query' field. By injecting a JavaScript payload containing document.cookie manipulation code, the researcher was able to set and persist a PHPSESSID cookie on the victim's device. This payload was executed by the browser, creating a persistent session cookie that allowed an attacker to maintain unauthorized sessions and gain access to other users' accounts without needing their login credentials. The vulnerability paid out $1,000, and the organization addressed it by implementing strong input validation and setting appropriate CSP headers—never trust user-controlled data for security decisions. Key lesson: Validate inputs and enforce strict Content Security Policies to prevent XSS attacks. #BugBounty #XSS #CSP #InputValidation #Infosec -
The Bouncer Who Never Checked IDs
This vulnerability was an XSS (Cross-Site Scripting) issue due to insufficient input validation and lack of Content Security Policy (CSP). The application accepted user input for a query parameter without proper sanitization, allowing script injection through the 'query' field. The researcher injected a payload containing JavaScript code that set a cookie named 'PHPSESSID', which is a unique session identifier in PHP applications. This payload was executed by the browser on the victim's device, creating a persistent session cookie. With this cookie, an attacker could maintain unauthorized sessions and gain access to other users' accounts without needing their login credentials. The vulnerability paid out $250, and the organization addressed it by implementing strong input validation and setting appropriate CSP headers—never trust user-controlled data for security decisions. Key lesson: Always validate inputs and enforce strict Content Security Policies. #BugBounty #XSS #CSP #InputValidation #Infosec -
How I Found a P1 Bug in a Bug Bounty Program (Step-by-Step Guide)
This article details the discovery of an XSS vulnerability due to insufficient input validation and lack of Content Security Policy (CSP). The application accepted user input for a query parameter without proper sanitization, allowing script injection through the 'query' field. By injecting a JavaScript payload containing document.cookie manipulation code, the researcher was able to set and persist a PHPSESSID cookie on the victim's device. This payload was executed by the browser, creating a persistent session cookie that allowed an attacker to maintain unauthorized sessions and gain access to other users' accounts without needing their login credentials. The vulnerability paid out $1,000, and the organization addressed it by implementing strong input validation and setting appropriate CSP headers—never trust user-controlled data for security decisions. Key lesson: Validate inputs and enforce strict Content Security Policies to prevent XSS attacks. #BugBounty #XSS #CSP #InputValidation #Infosec -
The Bouncer Who Never Checked IDs
This vulnerability was an XSS (Cross-Site Scripting) issue due to insufficient input validation and lack of Content Security Policy (CSP). The application accepted user input for a query parameter without proper sanitization, allowing script injection through the 'query' field. The researcher injected a payload containing JavaScript code that set a cookie named 'PHPSESSID', which is a unique session identifier in PHP applications. This payload was executed by the browser on the victim's device, creating a persistent session cookie. With this cookie, an attacker could maintain unauthorized sessions and gain access to other users' accounts without needing their login credentials. The vulnerability paid out $250, and the organization addressed it by implementing strong input validation and setting appropriate CSP headers—never trust user-controlled data for security decisions. Key lesson: Always validate inputs and enforce strict Content Security Policies. #BugBounty #XSS #CSP #InputValidation #Infosec -
Web Security Series #14 — Blind Command Injection Exploitation
This article discusses a Blind Command Injection (BCI) vulnerability in an unnamed web application. The root cause was the lack of input validation for the search field, which accepted user-supplied URLs without filtering malicious parameters such as '; command=ls'. This blind command injection allowed attackers to execute operating system commands by sending specially crafted payloads through the compromised search functionality. The researcher used a combination of Burp Suite's Intruder and Repeater tools to identify and exploit this vulnerability. The mechanism behind the flaw was the application interpreting these malicious commands as separate requests, returning error messages that could be interpreted by the attacker. The impact included potential unauthorized access and information disclosure (e.g., listing files using 'ls' command). The bounty amount or program response were not mentioned in the article. To remediate this issue, proper input validation must be implemented for user-supplied URLs, and servers should not execute external commands based on user input. Key lesson: Input validation is crucial for preventing Blind Command Injection attacks #BugBounty #WebSecurity #CommandInjection #InputValidation #Infosec -
Web Security Series #14 — Blind Command Injection Exploitation
This article discusses a Blind Command Injection (BCI) vulnerability in an unnamed web application. The root cause was the lack of input validation for the search field, which accepted user-supplied URLs without filtering malicious parameters such as '; command=ls'. This blind command injection allowed attackers to execute operating system commands by sending specially crafted payloads through the compromised search functionality. The researcher used a combination of Burp Suite's Intruder and Repeater tools to identify and exploit this vulnerability. The mechanism behind the flaw was the application interpreting these malicious commands as separate requests, returning error messages that could be interpreted by the attacker. The impact included potential unauthorized access and information disclosure (e.g., listing files using 'ls' command). The bounty amount or program response were not mentioned in the article. To remediate this issue, proper input validation must be implemented for user-supplied URLs, and servers should not execute external commands based on user input. Key lesson: Input validation is crucial for preventing Blind Command Injection attacks #BugBounty #WebSecurity #CommandInjection #InputValidation #Infosec -
How I Found Pre-Account Takeover Vulnerabilities
This bug involved an Authentication Bypass through insufficient input validation of URL parameters, enabling Account Takeover (ATO). The researcher discovered the application accepted and processed user-controlled URL parameters without proper sanitization. By crafting malicious links containing account tokens, the attacker could hijack users' active sessions simply by sharing these links via SMS or email. The underlying flaw was the failure to validate the authenticity of URL parameters before processing them. To exploit this vulnerability, the researcher generated malicious deep links containing account tokens and shared them with targeted victims. Due to inadequate input validation, the application trusted these links and processed them, resulting in unauthorized access to victim accounts. The researcher received a $4,000 bounty for disclosing this issue, and Microsoft promptly patched the vulnerability. To prevent similar ATO vulnerabilities, it is essential to thoroughly validate and sanitize all user-controlled inputs, including URL parameters. Key lesson: Always verify the authenticity of user-supplied data before processing it. #BugBounty #Cybersecurity #AuthenticationTakeover #InputValidation #Infosec -
How I Found Pre-Account Takeover Vulnerabilities
This bug involved a critical Account Takeover (ATO) due to insufficient input validation. The researcher discovered that the application accepted and processed URL parameters without proper sanitization, enabling an attacker to craft malicious links with embedded access tokens. These links could be shared via SMS or email, allowing an attacker to hijack users' active sessions without requiring any user interaction other than clicking the link. The underlying flaw was the failure to validate the authenticity of URL parameters before processing them. To exploit this vulnerability, the researcher generated malicious deep links containing account tokens and shared them with targeted victims. Due to inadequate input validation, the application trusted these links and processed them, resulting in unauthorized access to victim accounts. The researcher received a $4,000 bounty for disclosing this issue, and Microsoft promptly patched the vulnerability. To prevent similar ATO vulnerabilities, it is essential to thoroughly validate and sanitize all user-controlled inputs, including URL parameters. Key lesson: Always verify the authenticity of user-supplied data before processing it. #BugBounty #Cybersecurity #AuthenticationTakeover #InputValidation #Infosec -
How I Found Pre-Account Takeover Vulnerabilities
This bug involved a critical Account Takeover (ATO) due to insufficient input validation. The researcher discovered that the application accepted and processed URL parameters without proper sanitization, enabling an attacker to craft malicious links with embedded access tokens. These links could be shared via SMS or email, allowing an attacker to hijack users' active sessions without requiring any user interaction other than clicking the link. The underlying flaw was the failure to validate the authenticity of URL parameters before processing them. To exploit this vulnerability, the researcher generated malicious deep links containing account tokens and shared them with targeted victims. Due to inadequate input validation, the application trusted these links and processed them, resulting in unauthorized access to victim accounts. The researcher received a $4,000 bounty for disclosing this issue, and Microsoft promptly patched the vulnerability. To prevent similar ATO vulnerabilities, it is essential to thoroughly validate and sanitize all user-controlled inputs, including URL parameters. Key lesson: Always verify the authenticity of user-supplied data before processing it. #BugBounty #Cybersecurity #AuthenticationTakeover #InputValidation #Infosec -
How I Found Pre-Account Takeover Vulnerabilities
This bug involved an Authentication Bypass through insufficient input validation of URL parameters, enabling Account Takeover (ATO). The researcher discovered the application accepted and processed user-controlled URL parameters without proper sanitization. By crafting malicious links containing account tokens, the attacker could hijack users' active sessions simply by sharing these links via SMS or email. The underlying flaw was the failure to validate the authenticity of URL parameters before processing them. To exploit this vulnerability, the researcher generated malicious deep links containing account tokens and shared them with targeted victims. Due to inadequate input validation, the application trusted these links and processed them, resulting in unauthorized access to victim accounts. The researcher received a $4,000 bounty for disclosing this issue, and Microsoft promptly patched the vulnerability. To prevent similar ATO vulnerabilities, it is essential to thoroughly validate and sanitize all user-controlled inputs, including URL parameters. Key lesson: Always verify the authenticity of user-supplied data before processing it. #BugBounty #Cybersecurity #AuthenticationTakeover #InputValidation #Infosec -
كيف اكتشفتُ ثغرات أمنية قبل اختراق الحساب عدة مرات — دليل سهل للمبتدئين
This article discusses a Cross-Site Scripting (XSS) vulnerability in a web application. The root cause was improper input validation and sanitization, allowing malicious scripts to be injected into the application through user inputs such as comments. The attacker discovered this by observing error messages that indicated script injection (e.g., 'Uncaught SyntaxError'). By exploiting this vulnerability, an attacker could steal user sessions, perform unauthorized actions, or redirect users to malicious sites. The bounty amount was not disclosed, but the article mentions a fix through content security policy (CSP) implementation and input validation on both client-side and server-side scripts. Key lesson: Always validate and sanitize user inputs on all layers of your application to prevent XSS attacks. #BugBounty #WebSecurity #XSS #InputValidation #Infosec -
كيف اكتشفتُ ثغرات أمنية قبل اختراق الحساب عدة مرات — دليل سهل للمبتدئين
This article discusses a Cross-Site Scripting (XSS) vulnerability in a web application. The root cause was improper input validation and sanitization, allowing malicious scripts to be injected into the application through user inputs such as comments. The attacker discovered this by observing error messages that indicated script injection (e.g., 'Uncaught SyntaxError'). By exploiting this vulnerability, an attacker could steal user sessions, perform unauthorized actions, or redirect users to malicious sites. The bounty amount was not disclosed, but the article mentions a fix through content security policy (CSP) implementation and input validation on both client-side and server-side scripts. Key lesson: Always validate and sanitize user inputs on all layers of your application to prevent XSS attacks. #BugBounty #WebSecurity #XSS #InputValidation #Infosec -
Exploiting SQL Injection to Bypass Login Authentication | PortSwigger Lab Write-up
This vulnerability was an SQL Injection in the login authentication process, bypassing user validation. The application did not sanitize user inputs, allowing an attacker to inject malicious SQL code ('; --') into the email field during login. By using the Burp Suite Intruder tool with a SQL injection payload, the researcher discovered the vulnerability and exploited it to bypass login authentication by executing a blind SQL injection (extracting the salt value). The attacker then used the salt value and a dictionary attack to crack the password hash. The impact included unauthorized access to user accounts. The researcher received 500 points in the PortSwigger Lab (an online platform for learning web application security). Proper mitigation requires input validation and sanitization to prevent SQL injection attacks. Key lesson: Always validate and sanitize user inputs to prevent SQL injection attacks. #BugBounty #Cybersecurity #WebSecurity #SQLInjection #InputValidation -
Exploiting SQL Injection to Bypass Login Authentication | PortSwigger Lab Write-up
This vulnerability was an SQL Injection in the login authentication process, bypassing user validation. The application did not sanitize user inputs, allowing an attacker to inject malicious SQL code ('; --') into the email field during login. By using the Burp Suite Intruder tool with a SQL injection payload, the researcher discovered the vulnerability and exploited it to bypass login authentication by executing a blind SQL injection (extracting the salt value). The attacker then used the salt value and a dictionary attack to crack the password hash. The impact included unauthorized access to user accounts. The researcher received 500 points in the PortSwigger Lab (an online platform for learning web application security). Proper mitigation requires input validation and sanitization to prevent SQL injection attacks. Key lesson: Always validate and sanitize user inputs to prevent SQL injection attacks. #BugBounty #Cybersecurity #WebSecurity #SQLInjection #InputValidation -
How I Found a Critical IDOR Leading to Account Takeover in Two EdTech Platforms
The vulnerability was an Insecure Direct Object Reference (IDOR) in two EdTech platforms, allowing account takeover through user profile manipulation. The flaw resulted from improper input validation, leading to user profiles being accessible via URL parameters. By constructing carefully crafted URLs containing other users' IDs, the researcher accessed their profiles without proper authentication. The attack vector involved using Burp Suite's Intruder tool to automate IDOR requests, sending payloads with incremental user IDs. The mechanism revolved around the application trusting the provided IDs without verifying their ownership or performing proper authorization checks. This IDOR flaw enabled the researcher to impersonate other users, potentially causing serious account takeovers. The researcher did not disclose specific bounty amounts or program responses. Proper mitigation requires implementing strict input validation and enforcing proper access control checks. Key lesson: Always validate user inputs and enforce proper access control to prevent unauthorized data access. #BugBounty #Cybersecurity #WebSecurity #IDOR #AccountTakeover #InputValidation -
How I Found a Critical IDOR Leading to Account Takeover in Two EdTech Platforms
The vulnerability was an Insecure Direct Object Reference (IDOR) in two EdTech platforms, allowing account takeover through user profile manipulation. The flaw resulted from improper input validation, leading to user profiles being accessible via URL parameters. By constructing carefully crafted URLs containing other users' IDs, the researcher accessed their profiles without proper authentication. The attack vector involved using Burp Suite's Intruder tool to automate IDOR requests, sending payloads with incremental user IDs. The mechanism revolved around the application trusting the provided IDs without verifying their ownership or performing proper authorization checks. This IDOR flaw enabled the researcher to impersonate other users, potentially causing serious account takeovers. The researcher did not disclose specific bounty amounts or program responses. Proper mitigation requires implementing strict input validation and enforcing proper access control checks. Key lesson: Always validate user inputs and enforce proper access control to prevent unauthorized data access. #BugBounty #Cybersecurity #WebSecurity #IDOR #AccountTakeover #InputValidation -
Forbidden Does’t Mean Impossible — Discovering Hidden Endpoints with 403Bypasser
In this article, the researcher discovered a technique for bypassing 403 Forbidden errors and uncovering hidden endpoints. The vulnerability stemmed from a lack of proper error handling and insufficient input validation on the application's side. By using the 403Bypasser tool, the researcher sent crafted requests to test for potential bypasses. The payload contained an If-Modified-Since header with a future timestamp. If the response included a 200 OK status instead of the expected 403 Forbidden, it indicated that the endpoint was vulnerable. The researcher found that the application failed to handle invalid timestamps, allowing them to access sensitive information. This flaw could potentially lead to unauthorized data access or information disclosure. The researcher earned $1,500 for this discovery. Proper remediation involves implementing proper input validation for timestamps, as well as thorough error handling. Key lesson: Inadequate error handling and input validation can lead to information disclosure and bypassing intended access restrictions. #BugBounty #InformationDisclosure #403Bypasser #InputValidation #Cybersecurity #WebSecurity -
Critical Splunk RCE Vulnerability (CVE-2026–20163) Lets Attackers Run Shell Commands on Your Server
The discovered vulnerability is a Remote Code Execution (RCE) in Splunk, a popular data processing software. The flaw stems from insufficient input validation in the application's search interface. By constructing a crafted search query, an attacker can exploit the vulnerability and execute arbitrary shell commands on the target server. Specifically, an attacker can utilize the 'enableJavaScript' and 'enableCookies' search commands to trigger the RCE. When the search interface receives a request, it inadvertently executes JavaScript provided by the attacker, enabling further exploitation. The impact of this vulnerability is severe, as it allows unauthorized execution of commands with the privileges of the Splunk user, potentially leading to data breaches or unauthorized access. The researcher received a $15,000 bounty from Splunk for reporting this critical issue. To remediate, Splunk suggests implementing input validation and sanitization for user-supplied search queries. Key lesson: Always validate user inputs to prevent RCE attacks. #BugBounty #Cybersecurity #RCE #Splunk #InputValidation -
Logic Flaw in Meta Account Center: The Case of the Silent Patched Disavow Flow
This vulnerability is an Input Validation issue that enabled Sensitive Data Disclosure through the Meta Account Center. The root cause stems from a lack of input validation on the 'disavow' feature, which accepts URLs without proper filtering or validation. The researcher discovered this by submitting a crafted URL containing a base64-encoded payload (base64:php%20info()) to the disavow form. The payload was decoded on the server-side, leading to remote code execution and server information disclosure. The attacker could have gained access to sensitive data such as user session tokens, account credentials, or internal server data. After reporting the issue, Meta patched the vulnerability silently without a public disclosure or bounty payout. Proper remediation involves implementing input validation and sanitization for user-supplied URLs and sensitive data. Key lesson: Always validate and sanitize user inputs to prevent sensitive data disclosure or unauthorized access. #BugBounty #Cybersecurity #InputValidation #DataDisclosure #WebSecurity -
Critical Splunk RCE Vulnerability (CVE-2026–20163) Lets Attackers Run Shell Commands on Your Server
The discovered vulnerability is a Remote Code Execution (RCE) in Splunk, a popular data processing software. The flaw stems from insufficient input validation in the application's search interface. By constructing a crafted search query, an attacker can exploit the vulnerability and execute arbitrary shell commands on the target server. Specifically, an attacker can utilize the 'enableJavaScript' and 'enableCookies' search commands to trigger the RCE. When the search interface receives a request, it inadvertently executes JavaScript provided by the attacker, enabling further exploitation. The impact of this vulnerability is severe, as it allows unauthorized execution of commands with the privileges of the Splunk user, potentially leading to data breaches or unauthorized access. The researcher received a $15,000 bounty from Splunk for reporting this critical issue. To remediate, Splunk suggests implementing input validation and sanitization for user-supplied search queries. Key lesson: Always validate user inputs to prevent RCE attacks. #BugBounty #Cybersecurity #RCE #Splunk #InputValidation -
Logic Flaw in Meta Account Center: The Case of the Silent Patched Disavow Flow
This vulnerability is an Input Validation issue that enabled Sensitive Data Disclosure through the Meta Account Center. The root cause stems from a lack of input validation on the 'disavow' feature, which accepts URLs without proper filtering or validation. The researcher discovered this by submitting a crafted URL containing a base64-encoded payload (base64:php%20info()) to the disavow form. The payload was decoded on the server-side, leading to remote code execution and server information disclosure. The attacker could have gained access to sensitive data such as user session tokens, account credentials, or internal server data. After reporting the issue, Meta patched the vulnerability silently without a public disclosure or bounty payout. Proper remediation involves implementing input validation and sanitization for user-supplied URLs and sensitive data. Key lesson: Always validate and sanitize user inputs to prevent sensitive data disclosure or unauthorized access. #BugBounty #Cybersecurity #InputValidation #DataDisclosure #WebSecurity -
Forbidden Does’t Mean Impossible — Discovering Hidden Endpoints with 403Bypasser
In this article, the researcher discovered a technique for bypassing 403 Forbidden errors and uncovering hidden endpoints. The vulnerability stemmed from a lack of proper error handling and insufficient input validation on the application's side. By using the 403Bypasser tool, the researcher sent crafted requests to test for potential bypasses. The payload contained an If-Modified-Since header with a future timestamp. If the response included a 200 OK status instead of the expected 403 Forbidden, it indicated that the endpoint was vulnerable. The researcher found that the application failed to handle invalid timestamps, allowing them to access sensitive information. This flaw could potentially lead to unauthorized data access or information disclosure. The researcher earned $1,500 for this discovery. Proper remediation involves implementing proper input validation for timestamps, as well as thorough error handling. Key lesson: Inadequate error handling and input validation can lead to information disclosure and bypassing intended access restrictions. #BugBounty #InformationDisclosure #403Bypasser #InputValidation #Cybersecurity #WebSecurity -
IDOR Mastery: From Basic ID Changes to Advanced Techniques That Pay $10K+ Bounties
This article details Insecure Direct Object Reference (IDOR) exploitation techniques, some resulting in $10,000+ bug bounty payouts. The root cause of these vulnerabilities lies in developers not validating user-controlled inputs when accessing other users' data, leading to unauthorized access and data disclosure. The researcher demonstrated various IDOR techniques using simple ID swapping and advanced methods like time-based and content-based blind IDOR, as well as chaining IDOR with other vulnerabilities. These techniques allow attackers to manipulate and access data they should not have access to. The payout amounts ranged from $1,000 to $15,000, with programs responding quickly and taking the vulnerabilities seriously. Remediation includes input validation, access control, and authorization checks. Key lesson: Always validate user-controlled inputs when accessing other users' data to prevent IDOR vulnerabilities. #BugBounty #WebSecurity #IDOR #Cybersecurity #InputValidation -
IDOR Mastery: From Basic ID Changes to Advanced Techniques That Pay $10K+ Bounties
This article details Insecure Direct Object Reference (IDOR) exploitation techniques, some resulting in $10,000+ bug bounty payouts. The root cause of these vulnerabilities lies in developers not validating user-controlled inputs when accessing other users' data, leading to unauthorized access and data disclosure. The researcher demonstrated various IDOR techniques using simple ID swapping and advanced methods like time-based and content-based blind IDOR, as well as chaining IDOR with other vulnerabilities. These techniques allow attackers to manipulate and access data they should not have access to. The payout amounts ranged from $1,000 to $15,000, with programs responding quickly and taking the vulnerabilities seriously. Remediation includes input validation, access control, and authorization checks. Key lesson: Always validate user-controlled inputs when accessing other users' data to prevent IDOR vulnerabilities. #BugBounty #WebSecurity #IDOR #Cybersecurity #InputValidation -
Part 2 Outline: High-Impact Bugs Without Heavy Scanning
This article highlights a subtle vulnerability in applications that require JavaScript and cookies to function. By disabling these features, a researcher can potentially bypass critical functionality like login forms or sensitive pages. The root cause lies in the application's assumption that if JavaScript is enabled and cookies are present, user interactions are legitimate. During testing, the researcher discovered an input validation flaw where sanitization didn't occur on disabled JavaScript states, allowing for injection of malicious payloads. This led to unauthorized access and potential data breaches if sensitive information was exposed. The researcher received a substantial bounty but did not disclose the exact amount in the article. To prevent such vulnerabilities, it's essential to validate inputs even when JavaScript is disabled and enforce proper sanitization on user input. Key lesson: Never assume legitimate user interactions solely based on enabled JavaScript or present cookies #BugBounty #WebSecurity #InputValidation #AuthenticationBypass #XSS -
Part 2 Outline: High-Impact Bugs Without Heavy Scanning
This article highlights a subtle vulnerability in applications that require JavaScript and cookies to function. By disabling these features, a researcher can potentially bypass critical functionality like login forms or sensitive pages. The root cause lies in the application's assumption that if JavaScript is enabled and cookies are present, user interactions are legitimate. During testing, the researcher discovered an input validation flaw where sanitization didn't occur on disabled JavaScript states, allowing for injection of malicious payloads. This led to unauthorized access and potential data breaches if sensitive information was exposed. The researcher received a substantial bounty but did not disclose the exact amount in the article. To prevent such vulnerabilities, it's essential to validate inputs even when JavaScript is disabled and enforce proper sanitization on user input. Key lesson: Never assume legitimate user interactions solely based on enabled JavaScript or present cookies #BugBounty #WebSecurity #InputValidation #AuthenticationBypass #XSS -
[PortSwigger][Practitioner] - Lab: CSRF where token is not tied to user session
In this lab, the vulnerability was Cross-Site Request Forgery (CSRF), caused by a lack of proper synchronization between the CSRF token and user sessions. The application issued CSRF tokens for all requests without tying them to active user sessions, allowing an attacker to exploit unintended actions on behalf of the victim. The researcher used Burp Suite's Intruder tool to inject a malicious payload into a victim's browser through a phishing email or other means. By exploiting this flaw, the attacker could execute unwanted account changes or data manipulation, as the application accepted user requests without verifying their origin. The impact included unauthorized actions and potential privacy breaches. Remediation includes tying CSRF tokens to active user sessions during token generation. Key lesson: Always ensure proper synchronization between CSRF tokens and user sessions to prevent CSRF attacks. #BugBounty #Cybersecurity #WebSecurity #CSRF #InputValidation -
Exploiting DOM Clobbering to Enable DOM-Based XSS
This article discusses a DOM-based Cross-Site Scripting (XSS) vulnerability, exploited through manipulation of JavaScript variables. The root cause was the application's failure to sanitize user inputs when setting object properties, leading to data injection into sensitive contexts. By using DOM clobbering (overwriting existing JavaScript variables with malicious payloads), the researcher was able to insert arbitrary scripts within the vulnerable domain's context. This attack vector allowed for injecting and executing XSS payloads without relying on reflected or stored attacks. The technical details demonstrate that sensitive information could be leaked or modified by an attacker through this flaw, leading to privacy breaches and potential account takeovers. The researcher reported the vulnerability, received a bounty reward, and encouraged developers to sanitize user inputs when setting object properties and apply Content Security Policy (CSP) with appropriate directives. Key lesson: Always validate user inputs and be mindful of JavaScript variable assignments to prevent DOM-based XSS attacks. #BugBounty #WebSecurity #XSS #InputValidation #DOM -
Cross-Site Request Forgery (CSRF): A Practical Methodology for Security Testing
This article presents a practical approach to detect Cross-Site Request Forgery (CSRF) vulnerabilities in web applications. The root cause of CSRF is insufficient input validation, which allows an attacker to manipulate user sessions and perform unintended actions on behalf of the victim. The researcher utilized Burp Suite's Intercept feature to intercept a request containing a vulnerable form (e.g., update password) and crafted a malicious payload with a hidden iframe (e.g., <iframe src='https://attacker.com/csrf?id=123'>). By injecting this payload into another website, the attacker triggered the victim's browser to execute the vulnerable form request. The system did not verify the origin of the request, resulting in unauthorized account changes. Potential consequences include data breaches, account takeovers, and privacy violations. The researcher received a reward for reporting this flaw and encouraged developers to implement proper synchronization between CSRF tokens and user sessions, or use modern approaches like Content Security Policy (CSP) and Subresource Integrity (SRI). Key lesson: Always validate user inputs and verify the origin of requests to prevent CSRF attacks. #BugBounty #WebSecurity #CSRF #InputValidation -
Blind SQL Injection Attacks
This article discusses a blind SQL injection vulnerability, where the application did not properly sanitize user inputs when handling search queries. The researcher utilized error-based and time-based techniques to exploit this flaw. Error-based methods involved setting up separate requests with malicious payloads (e.g., ' OR 1=1 -- ') and analyzing server responses for SQL errors or syntax issues. Time-based techniques relied on manipulating the timing of responses between valid and invalid queries to identify the presence of SQL injection points. By exploiting this flaw, an attacker could potentially retrieve sensitive data such as passwords, emails, and user details. The researcher received a bounty reward and encouraged developers to sanitize user inputs using parameterized queries or stored procedures, input validation, and limiting the execution scope of user-supplied data (e.g., preventing UNION and SELECT statements). Key lesson: Always validate user inputs and use parametrized queries for SQL-based operations to prevent blind SQL injection attacks. #BugBounty #Cybersecurity #WebSecurity #SQLInjection #InputValidation -
Exploiting DOM Clobbering to Enable DOM-Based XSS
This article discusses a DOM-based Cross-Site Scripting (XSS) vulnerability, exploited through manipulation of JavaScript variables. The root cause was the application's failure to sanitize user inputs when setting object properties, leading to data injection into sensitive contexts. By using DOM clobbering (overwriting existing JavaScript variables with malicious payloads), the researcher was able to insert arbitrary scripts within the vulnerable domain's context. This attack vector allowed for injecting and executing XSS payloads without relying on reflected or stored attacks. The technical details demonstrate that sensitive information could be leaked or modified by an attacker through this flaw, leading to privacy breaches and potential account takeovers. The researcher reported the vulnerability, received a bounty reward, and encouraged developers to sanitize user inputs when setting object properties and apply Content Security Policy (CSP) with appropriate directives. Key lesson: Always validate user inputs and be mindful of JavaScript variable assignments to prevent DOM-based XSS attacks. #BugBounty #WebSecurity #XSS #InputValidation #DOM -
[PortSwigger][Practitioner] - Lab: CSRF where token is not tied to user session
In this lab, the vulnerability was Cross-Site Request Forgery (CSRF), caused by a lack of proper synchronization between the CSRF token and user sessions. The application issued CSRF tokens for all requests without tying them to active user sessions, allowing an attacker to exploit unintended actions on behalf of the victim. The researcher used Burp Suite's Intruder tool to inject a malicious payload into a victim's browser through a phishing email or other means. By exploiting this flaw, the attacker could execute unwanted account changes or data manipulation, as the application accepted user requests without verifying their origin. The impact included unauthorized actions and potential privacy breaches. Remediation includes tying CSRF tokens to active user sessions during token generation. Key lesson: Always ensure proper synchronization between CSRF tokens and user sessions to prevent CSRF attacks. #BugBounty #Cybersecurity #WebSecurity #CSRF #InputValidation -
Cross-Site Request Forgery (CSRF): A Practical Methodology for Security Testing
This article presents a practical approach to detect Cross-Site Request Forgery (CSRF) vulnerabilities in web applications. The root cause of CSRF is insufficient input validation, which allows an attacker to manipulate user sessions and perform unintended actions on behalf of the victim. The researcher utilized Burp Suite's Intercept feature to intercept a request containing a vulnerable form (e.g., update password) and crafted a malicious payload with a hidden iframe (e.g., <iframe src='https://attacker.com/csrf?id=123'>). By injecting this payload into another website, the attacker triggered the victim's browser to execute the vulnerable form request. The system did not verify the origin of the request, resulting in unauthorized account changes. Potential consequences include data breaches, account takeovers, and privacy violations. The researcher received a reward for reporting this flaw and encouraged developers to implement proper synchronization between CSRF tokens and user sessions, or use modern approaches like Content Security Policy (CSP) and Subresource Integrity (SRI). Key lesson: Always validate user inputs and verify the origin of requests to prevent CSRF attacks. #BugBounty #WebSecurity #CSRF #InputValidation -
Blind SQL Injection Attacks
This article discusses a blind SQL injection vulnerability, where the application did not properly sanitize user inputs when handling search queries. The researcher utilized error-based and time-based techniques to exploit this flaw. Error-based methods involved setting up separate requests with malicious payloads (e.g., ' OR 1=1 -- ') and analyzing server responses for SQL errors or syntax issues. Time-based techniques relied on manipulating the timing of responses between valid and invalid queries to identify the presence of SQL injection points. By exploiting this flaw, an attacker could potentially retrieve sensitive data such as passwords, emails, and user details. The researcher received a bounty reward and encouraged developers to sanitize user inputs using parameterized queries or stored procedures, input validation, and limiting the execution scope of user-supplied data (e.g., preventing UNION and SELECT statements). Key lesson: Always validate user inputs and use parametrized queries for SQL-based operations to prevent blind SQL injection attacks. #BugBounty #Cybersecurity #WebSecurity #SQLInjection #InputValidation -
Bảo vệ tính toàn vẹn dữ liệu trong giai đoạn đỉnh điểm truy cập là thách thức lớn. Tấn côngInjection, bot spam, dữ liệu sai định dạng có thể làm hỏng hệ thống. Áp dụng biện pháp bảo mật: WAF chặn SQL injection, giới hạn tần suất request, xác thực CAPTCHA, lọc dữ liệu đầu vào, mã hóa TLS và phát hiện bất thường bằng AI. #Cybersecurity #DataIntegrity #AnomalyDetection #InputValidation #WAF #BảoMậtDữLiệu #ToànVẹnDữLiêu #PhátHiệnBấtThường
https://dev.to/mohammad_waseem_c31f3a26f/securing-data-integ
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No error handling and no suitable tests for consumers of the feature file are, of course, also a tremendous trade-off between security, performance, and robustness. #resilience #inputvalidation🤷♂️🤦♂️
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No error handling and no suitable tests for consumers of the feature file are, of course, also a tremendous trade-off between security, performance, and robustness. #resilience #inputvalidation🤷♂️🤦♂️
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No error handling and no suitable tests for consumers of the feature file are, of course, also a tremendous trade-off between security, performance, and robustness. #resilience #inputvalidation🤷♂️🤦♂️
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No error handling and no suitable tests for consumers of the feature file are, of course, also a tremendous trade-off between security, performance, and robustness. #resilience #inputvalidation🤷♂️🤦♂️
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No error handling and no suitable tests for consumers of the feature file are, of course, also a tremendous trade-off between security, performance, and robustness. #resilience #inputvalidation🤷♂️🤦♂️
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Business Logic Flaw: How an Empty Team Name Can Trap Users Forever
This bug bounty analysis reveals a critical **Business Logic Vulnerability** stemming from missing input validation that enables permanent user account entrapment. The vulnerability exploits inadequate team name validation in GraphQL mutations, allowing attackers to set team names to empty space or whitespace characters. The exploitation chain involves: (1) An attacker with owner privileges changes the team name to empty space via the `updateTeam` GraphQL mutation, (2) When legitimate users attempt to leave the team using the `leaveTeam` function, they encounter an impossible confirmation step requiring them to type the team name for verification, (3) Since the team name appears empty/blank in the UI, users cannot complete the confirmation process and become permanently trapped within the organization. This creates a **Denial of Service** attack against user account mobility and violates fundamental user rights to control their digital presence. The root cause is insufficient input validation that fails to check for empty, whitespace-only, or minimal-length team names, combined with brittle business logic that depends entirely on team name visibility without implementing fallback mechanisms. The vulnerability has severe business implications including customer experience damage, increased support costs, reputation damage, and potential GDPR/CCPA compliance violations. Mitigation requires implementing comprehensive input validation with minimum length requirements (at least 2 characters), storing original team names for recovery purposes, providing alternative confirmation methods (creation date, member count), and implementing admin override capabilities. Organizations must also redesign destructive operations with multiple escape hatches and test business logic edge cases including empty values and special characters. The vulnerability demonstrates how simple input validation failures can create catastrophic user experience issues and permanent security states that cannot be resolved without manual intervention. #infosec #BugBounty #BusinessLogic #InputValidation #UserEnttrapment
https://medium.com/@aminouji23/business-logic-flaw-how-an-empty-team-name-can-trap-users-forever-fb9152acb990?source=rss------bug_bounty-5 -
Business Logic Flaw: How an Empty Team Name Can Trap Users Forever
This bug bounty analysis reveals a critical **Business Logic Vulnerability** stemming from missing input validation that enables permanent user account entrapment. The vulnerability exploits inadequate team name validation in GraphQL mutations, allowing attackers to set team names to empty space or whitespace characters. The exploitation chain involves: (1) An attacker with owner privileges changes the team name to empty space via the `updateTeam` GraphQL mutation, (2) When legitimate users attempt to leave the team using the `leaveTeam` function, they encounter an impossible confirmation step requiring them to type the team name for verification, (3) Since the team name appears empty/blank in the UI, users cannot complete the confirmation process and become permanently trapped within the organization. This creates a **Denial of Service** attack against user account mobility and violates fundamental user rights to control their digital presence. The root cause is insufficient input validation that fails to check for empty, whitespace-only, or minimal-length team names, combined with brittle business logic that depends entirely on team name visibility without implementing fallback mechanisms. The vulnerability has severe business implications including customer experience damage, increased support costs, reputation damage, and potential GDPR/CCPA compliance violations. Mitigation requires implementing comprehensive input validation with minimum length requirements (at least 2 characters), storing original team names for recovery purposes, providing alternative confirmation methods (creation date, member count), and implementing admin override capabilities. Organizations must also redesign destructive operations with multiple escape hatches and test business logic edge cases including empty values and special characters. The vulnerability demonstrates how simple input validation failures can create catastrophic user experience issues and permanent security states that cannot be resolved without manual intervention. #infosec #BugBounty #BusinessLogic #InputValidation #UserEnttrapment
https://medium.com/@aminouji23/business-logic-flaw-how-an-empty-team-name-can-trap-users-forever-fb9152acb990?source=rss------bug_bounty-5 -
Today is my #Python #Blog post where I learned about Input Validation. I'm learning as I write so be kind :) Post: www.spsanderson.com/steveondata/... #InputValidation #PyInputPlus #Python #Tech
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Today's one of the few times when #rust's error handling surprised me. I was using a range with values taken from the user, and forgot to validate. Usually when rust knows something can go wrong it issues a result, or an option, but not in this case, so the program panics if the user enters the wrong thing.
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Today's one of the few times when #rust's error handling surprised me. I was using a range with values taken from the user, and forgot to validate. Usually when rust knows something can go wrong it issues a result, or an option, but not in this case, so the program panics if the user enters the wrong thing.
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Today's one of the few times when #rust's error handling surprised me. I was using a range with values taken from the user, and forgot to validate. Usually when rust knows something can go wrong it issues a result, or an option, but not in this case, so the program panics if the user enters the wrong thing.
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Today's one of the few times when #rust's error handling surprised me. I was using a range with values taken from the user, and forgot to validate. Usually when rust knows something can go wrong it issues a result, or an option, but not in this case, so the program panics if the user enters the wrong thing.
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Today's one of the few times when #rust's error handling surprised me. I was using a range with values taken from the user, and forgot to validate. Usually when rust knows something can go wrong it issues a result, or an option, but not in this case, so the program panics if the user enters the wrong thing.
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Just added some filtering to the application I maintain. Some freaky user succeeded to enter a "START OF TEXT" character (unicode: u0002). We are still not sure how. I needed to hex edit a text file to create it so I could copy & paste it into a text field. #weirdusers #programming #inputvalidation
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Just added some filtering to the application I maintain. Some freaky user succeeded to enter a "START OF TEXT" character (unicode: u0002). We are still not sure how. I needed to hex edit a text file to create it so I could copy & paste it into a text field. #weirdusers #programming #inputvalidation
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Update (2020-04-29): Twitter has fixed their oversight.
{ "errors": [{ "code": 356, "message": "preferences.gender_preferences.gender_override: Must provide a non-empty custom value 30 characters or less in length." }]}Anyone who set their custom gender to a long volume of text, should still have it set to a long volume of text.
The original article follows after the separator.
I was recently made aware of a change to Twitter, which exposes a new Gender field. If you’ve never specified your gender before, they guessed what it was (which is a really shitty thing to do, especially towards trans folks!).
https://twitter.com/leemandelo/status/1254179716451438592
Slightly annoyed, I went to go see what Twitter thinks my gender is.
Curses! They know I’m a guy. This won’t do at all.
But what’s this? An “Add your gender” option?
That’s at least, something, I guess? Defaulting to [whatever the algorithm guesses] is sucky, but at least nonbinary folks can still self-identify however they want.
But 30 characters isn’t a lot. What if I want to drop in, say, 68 characters? Do I need to do some crazy Unicode fuckery to pull that off?
Nope, Inspect Element + set
maxlength="255"and now Twitter thinks my gender is the EICAR test file. Wonderful!Which means: If someone downloads my Twitter data without my consent onto a workstation running antivirus software, the file will delete itself and all will be right in the marketing world.
https://twitter.com/SoatokDhole/status/1254635753319079937
(Okay but seriously, a lot of downstream systemic failures would have to exist for any damage to occur from me deciding to self-identify to marketers this way.)
Lessons to Learn
Twitter enforced a maxlength of 30 in the HTML element of the “Add your gender” text input, but they didn’t enforce this requirement server-side. The takeaway here is pretty obvious.
Also, don’t try to automatically guess people’s gender at scale. It’s insulting when you get it wrong, and it’s creepy when you get it right.
(This sticker is tongue-in-cheek.)What’s the Upper Limit for the Field?
I don’t know, but this indicates it has a larger upper bound than a tweet.
https://twitter.com/txlon5/status/1254648412261228545
If anyone has success dropping an entire thesis on gender identity and culture in the Gender field, let me know.
Update: The Best Genders
Everyone is having a lot of fun with the Gender field. Here’s some of the best tweets I’ve seen since publishing this stupid bug.
https://twitter.com/TecraFox/status/1254653500887310337
https://twitter.com/everlasting1der/status/1254652388713082880
https://twitter.com/hedgehog_emoji/status/1254650551473594368
https://twitter.com/Neybulot/status/1254659048886210563
A fox in Furry Technologists suggested building genderfs, which is a lot like redditfs but hoists the entire filesystem into the Gender field.
While I have your attention, trans rights are human rights and biology disagrees with the simple notion of “two sexes”. Thank you and good night.
https://soatok.blog/2020/04/27/why-server-side-input-validation-matters/
#furry #infosec #inputValidation #LGBTQIA_ #security #softwareDevelopment #Twitter