CVE-2012-4533 in viewvc
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in the "extra" details in the DiffSource._get_row function in lib/viewvc.py in ViewVC 1.0.x before 1.0.13 and 1.1.x before 1.1.16 allows remote authenticated users with repository commit access to inject arbitrary web script or HTML via the "function name" line.
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Analysis
by VulDB Data Team • 12/20/2021
The CVE-2012-4533 vulnerability represents a critical cross-site scripting flaw discovered in the ViewVC web-based version control system. This vulnerability exists within the DiffSource._get_row function in the lib/viewvc.py file, affecting ViewVC versions 1.0.x prior to 1.0.13 and 1.1.x prior to 1.1.16. The flaw specifically targets the "extra" details section where user-provided data is processed without adequate sanitization, creating a pathway for malicious script injection. The vulnerability is particularly concerning because it requires only authenticated access with repository commit privileges, meaning that users who can commit changes to a repository can exploit this weakness to inject arbitrary web scripts or HTML code.
The technical implementation of this vulnerability stems from improper input validation and output encoding within the DiffSource._get_row function. When processing repository changes, the system fails to properly escape or sanitize user-supplied function names that appear in the "function name" line of the diff output. This allows an authenticated attacker with commit access to insert malicious payloads that will execute in the context of other users' browsers when they view the affected repository pages. The vulnerability is classified as a reflected XSS attack since the malicious content is injected into the server response and then executed by the victim's browser. This type of vulnerability falls under CWE-79 which specifically addresses Cross-Site Scripting flaws, and aligns with ATT&CK technique T1566.001 for Initial Access through malicious content.
The operational impact of this vulnerability extends beyond simple script execution, as it can enable attackers to perform session hijacking, steal sensitive information, manipulate repository views, or redirect users to malicious websites. An attacker with commit access could craft function names containing malicious JavaScript that would execute whenever other users browse the repository's diff views, potentially compromising the entire user base that accesses the affected system. The vulnerability's exploitation requires minimal privileges, making it particularly dangerous in environments where commit access is granted to multiple developers. Organizations relying on ViewVC for repository browsing and code review could face significant security implications, including potential data exfiltration and unauthorized access to sensitive source code repositories.
Mitigation strategies for CVE-2012-4533 should prioritize immediate patching of affected ViewVC installations to versions 1.0.13 or 1.1.16 and later. System administrators should implement proper input validation and output encoding mechanisms throughout the application, particularly in functions that process user-supplied data for display. Additional protective measures include implementing content security policies, regular security audits of web applications, and restricting commit privileges to only essential personnel. The vulnerability demonstrates the importance of proper sanitization of user inputs in web applications, especially in systems that display repository metadata and code changes. Organizations should also consider implementing web application firewalls and monitoring for suspicious commit patterns that might indicate attempted exploitation of similar vulnerabilities. This incident underscores the critical need for security-conscious development practices and regular vulnerability assessments in version control systems that serve as central access points for development teams.