CVE-2006-5442 in ViewVC
Summary
by MITRE
ViewVC 1.0.2 and earlier does not specify a charset in its HTTP headers or HTML documents, which allows remote attackers to conduct cross-site scripting (XSS) attacks that inject arbitrary UTF-7 encoded JavaScript code via a view.
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Analysis
by VulDB Data Team • 04/25/2026
The vulnerability identified as CVE-2006-5442 affects ViewVC versions 1.0.2 and earlier, representing a significant security flaw in web-based version control browsing systems. This issue stems from the application's failure to properly declare character encoding in its HTTP headers and HTML documents, creating an environment where malicious actors can exploit cross-site scripting vulnerabilities to inject harmful JavaScript code. The vulnerability specifically allows attackers to leverage UTF-7 encoding to bypass traditional security measures and execute arbitrary code within the context of a user's browser session.
The technical flaw manifests when ViewVC fails to specify a charset parameter in its Content-Type HTTP headers or in the HTML document's meta tags. This omission creates a parsing ambiguity that enables attackers to craft malicious input using UTF-7 encoding, which the application's XSS protection mechanisms may not adequately filter. When users browse repositories through the vulnerable ViewVC interface, the application's lack of explicit character encoding specification allows the browser to make assumptions about the encoding, which attackers can manipulate to inject JavaScript code that executes in the user's browser context. This represents a classic case of improper input validation and output encoding, where the system fails to properly sanitize or encode data before rendering it in the browser.
The operational impact of this vulnerability is substantial, as it enables remote attackers to conduct persistent cross-site scripting attacks without requiring any special privileges or access to the underlying system. An attacker could exploit this vulnerability by crafting repository browsing URLs or file contents that contain UTF-7 encoded JavaScript payloads, which would execute when users view the affected content. This creates a vector for session hijacking, data theft, and potential privilege escalation within the context of the user's browser session. The vulnerability affects any user who accesses repositories through the vulnerable ViewVC interface, making it particularly dangerous in collaborative development environments where multiple users interact with shared repositories.
The vulnerability aligns with CWE-116, which addresses improper encoding or escaping of output, and represents a failure in proper input validation and output encoding practices. From an ATT&CK framework perspective, this vulnerability maps to T1566, which covers Phishing with Pretext, and T1059, which involves Command and Scripting Interpreter. Organizations using vulnerable versions of ViewVC should immediately implement mitigations including upgrading to a patched version that properly specifies character encoding in HTTP headers and HTML documents. Additional protective measures include implementing Content Security Policy headers, configuring proper input validation, and ensuring that all web applications explicitly declare their character encoding using appropriate HTTP headers and HTML meta tags to prevent browsers from making potentially insecure assumptions about data encoding.