CVE-2011-2976 in Bugzilla
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in Bugzilla 2.16rc1 through 2.22.7, 3.0.x through 3.3.x, and 3.4.x before 3.4.12 allows remote attackers to inject arbitrary web script or HTML via vectors involving a BUGLIST cookie.
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Analysis
by VulDB Data Team • 11/17/2021
The vulnerability identified as CVE-2011-2976 represents a critical cross-site scripting flaw affecting multiple versions of the Bugzilla bug tracking system. This vulnerability specifically targets versions ranging from 2.16rc1 through 2.22.7, 3.0.x through 3.3.x, and 3.4.x before 3.4.12, making it a widespread issue that impacted a significant portion of Bugzilla deployments during that period. The flaw resides in how the application handles the BUGLIST cookie parameter, which is commonly used for maintaining user session state and preference settings within the web interface.
The technical nature of this vulnerability stems from insufficient input validation and output encoding mechanisms within the Bugzilla application. When the system processes the BUGLIST cookie value, it fails to properly sanitize or escape user-supplied data before incorporating it into dynamic web content generation. This oversight creates an environment where malicious actors can inject arbitrary JavaScript code or HTML content that gets executed in the context of other users' browsers. The vulnerability is classified as a classic reflected XSS attack vector, where the malicious payload is transmitted through a cookie rather than traditional URL parameters, making it particularly challenging to detect and prevent through standard security measures.
The operational impact of this vulnerability extends beyond simple data theft or defacement, as it enables attackers to execute malicious code within the context of authenticated user sessions. This capability allows for session hijacking, privilege escalation, and the potential for lateral movement within organizational networks where Bugzilla serves as a critical collaboration platform. Attackers could exploit this vulnerability to gain unauthorized access to sensitive bug reports, modify project data, or even establish persistent backdoors within the system. The widespread nature of affected versions means that organizations relying on these older Bugzilla deployments faced significant risk exposure, particularly in environments where multiple users interact with the system regularly.
Organizations affected by this vulnerability should prioritize immediate patching to version 3.4.12 or higher, which contains the necessary fixes to properly sanitize cookie values before processing them in web output contexts. Security measures should also include implementing proper input validation at multiple layers of the application architecture, including cookie handling routines and output encoding mechanisms. The vulnerability aligns with CWE-79 which specifically addresses cross-site scripting flaws, and represents a technique commonly categorized under ATT&CK tactic TA0001 (Initial Access) through the use of web-based attack vectors. Network-based mitigations such as web application firewalls and cookie security policies can provide additional defense-in-depth layers, though the fundamental fix requires proper application-level input sanitization and output encoding practices that prevent the injection of untrusted data into dynamic web content generation processes.