CVE-2007-3930 in DokuWiki
Summary
by MITRE
Interpretation conflict between Microsoft Internet Explorer and DocuWiki before 2007-06-26b allows remote attackers to inject arbitrary JavaScript and conduct cross-site scripting (XSS) attacks when spellchecking UTF-8 encoded messages via the spell_utf8test function in lib/exe/spellcheck.php, which triggers HTML document identification and script execution by Internet Explorer even though the Content-Type header is text/plain.
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Analysis
by VulDB Data Team • 07/21/2021
The vulnerability identified as CVE-2007-3930 represents a critical interpretation conflict between Microsoft Internet Explorer and DocuWiki that enables remote attackers to execute arbitrary JavaScript code through cross-site scripting attacks. This flaw specifically affects DocuWiki versions prior to 2007-06-26b and occurs during spellchecking operations involving UTF-8 encoded messages. The vulnerability stems from the spell_utf8test function located in lib/exe/spellcheck.php, which processes user input without proper sanitization or validation mechanisms. When users submit UTF-8 encoded text through the spellchecking interface, the application fails to properly handle character encoding, creating an opportunity for malicious script injection.
The technical exploitation of this vulnerability relies on the inconsistent behavior between web browsers and the server-side application regarding HTML document identification and script execution. Microsoft Internet Explorer demonstrates a particular interpretation pattern where it automatically identifies and executes embedded scripts even when the Content-Type header is explicitly set to text/plain. This behavior creates a mismatch between the server's intended security posture and the browser's actual execution model, allowing attackers to bypass standard security measures that would normally prevent script execution in plain text contexts. The vulnerability specifically manifests when UTF-8 encoded messages are processed through the spellcheck functionality, where the application's lack of proper input validation enables attackers to inject malicious JavaScript code that executes in the victim's browser context.
The operational impact of this vulnerability extends beyond simple XSS attacks, as it provides attackers with the capability to perform session hijacking, steal sensitive information, redirect users to malicious websites, and potentially gain unauthorized access to user accounts. The attack vector is particularly concerning because it leverages legitimate application functionality rather than exploiting separate security flaws, making detection more difficult for security monitoring systems. The vulnerability affects all users who interact with the spellchecking feature of affected DocuWiki installations, creating a widespread risk across organizations that rely on this wiki platform for collaborative work environments. The timing of the vulnerability's discovery and patch release indicates that it was actively exploited in the wild before the security community could fully understand its scope and implications.
Organizations should implement immediate mitigations including updating to DocuWiki version 2007-06-26b or later, which contains the necessary patches to address the encoding interpretation conflict. Additional protective measures include implementing Content Security Policy headers to restrict script execution, filtering and sanitizing all user input before processing, and configuring web application firewalls to detect and block suspicious UTF-8 encoding patterns. The vulnerability aligns with CWE-79, which addresses cross-site scripting flaws, and maps to ATT&CK technique T1059.007 for script injection. Security teams should also consider implementing regular security assessments of web applications to identify similar interpretation conflicts between different browser implementations and server-side processing mechanisms. The incident underscores the importance of thorough testing across different browser environments and the need for consistent security policies that account for varying client-side interpretations of web content.