Bug Bounty ShortsHow 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
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
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
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
