CVE-2006-2741 in tinyBB
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in Epicdesigns tinyBB 0.3 allow remote attackers to inject arbitrary web script or HTML via the q parameter in forgot.php, which is echoed in an error message, and other unspecified vectors.
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Analysis
by VulDB Data Team • 07/28/2018
The vulnerability identified as CVE-2006-2741 represents a critical cross-site scripting flaw within the Epicdesigns tinyBB 0.3 bulletin board system that exposes users to potential malicious code execution. This vulnerability specifically manifests in the forgot.php script where the q parameter fails to properly sanitize user input before being reflected back in error messages, creating an exploitable XSS vector that can be leveraged by remote attackers to execute arbitrary web scripts or HTML code within the context of affected user sessions.
The technical implementation of this vulnerability stems from inadequate input validation and output encoding mechanisms within the tinyBB application's password recovery functionality. When users submit requests through the forgot.php script, the q parameter containing user-supplied data is directly incorporated into error messages without proper sanitization or HTML escaping procedures. This flaw aligns with CWE-79, which categorizes cross-site scripting vulnerabilities as weaknesses in input validation and output encoding, where untrusted data flows into web pages without proper protection mechanisms. The vulnerability operates through the standard XSS attack pattern where malicious scripts embedded in the q parameter are executed when the error message is rendered in the victim's browser, potentially stealing session cookies, redirecting users to malicious sites, or performing unauthorized actions on behalf of authenticated users.
The operational impact of this vulnerability extends beyond simple script injection, creating significant security risks for both individual users and the overall system integrity. Attackers can exploit this weakness to hijack user sessions, modify forum content, or redirect users to phishing sites that appear legitimate within the context of the vulnerable application. The unspecified vectors mentioned in the description suggest that similar input handling flaws may exist elsewhere within the tinyBB 0.3 codebase, potentially affecting multiple endpoints and increasing the attack surface. This vulnerability particularly threatens user privacy and data confidentiality, as successful exploitation could lead to unauthorized access to private messages, user accounts, and potentially sensitive forum data. The impact is amplified by the fact that this vulnerability affects a core authentication mechanism, making it a prime target for attackers seeking persistent access to the forum environment.
Mitigation strategies for this vulnerability must address both immediate remediation and long-term architectural improvements to prevent similar issues. The primary solution involves implementing comprehensive input validation and output encoding for all user-supplied data, specifically ensuring that the q parameter in forgot.php and similar vectors are properly sanitized before being processed or displayed. This approach aligns with ATT&CK technique T1566, which covers social engineering attacks that often exploit XSS vulnerabilities to gain initial access to systems. Organizations should implement strict parameter validation using allowlists for acceptable input characters, employ context-appropriate output encoding for HTML, JavaScript, and URL contexts, and consider implementing Content Security Policy headers to limit script execution. Additionally, regular security audits and code reviews should be conducted to identify and remediate similar input validation weaknesses throughout the application codebase, ensuring that all user-facing parameters undergo proper sanitization before being incorporated into dynamic content or error messages. The vulnerability serves as a reminder of the critical importance of input validation in web applications and the potentially severe consequences when such protections are inadequate.