CVE-2012-3968 in Firefox
Summary
by MITRE
Use-after-free vulnerability in the WebGL implementation in Mozilla Firefox before 15.0, Firefox ESR 10.x before 10.0.7, Thunderbird before 15.0, Thunderbird ESR 10.x before 10.0.7, and SeaMonkey before 2.12 allows remote attackers to execute arbitrary code via vectors related to deletion of a fragment shader by its accessor.
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Analysis
by VulDB Data Team • 10/22/2024
The CVE-2012-3968 vulnerability represents a critical use-after-free flaw within the WebGL graphics implementation of Mozilla Firefox and related applications. This vulnerability specifically affects versions prior to Firefox 15.0, Firefox ESR 10.x before 10.0.7, Thunderbird 15.0, Thunderbird ESR 10.x before 10.0.7, and SeaMonkey 2.12. The flaw exists in how the browser handles fragment shader deletion operations within its WebGL rendering pipeline, creating a scenario where memory that has been freed can still be accessed by malicious code.
The technical nature of this vulnerability stems from improper memory management during WebGL fragment shader operations. When a fragment shader is deleted through its accessor, the WebGL implementation fails to properly invalidate references to the freed memory region. This creates a use-after-free condition where an attacker can manipulate the graphics rendering process to cause the application to access memory that has already been deallocated, potentially leading to arbitrary code execution. The vulnerability operates at the intersection of graphics API handling and memory management, making it particularly dangerous as it leverages the complex WebGL rendering context to achieve exploitation.
The operational impact of this vulnerability is severe, as it enables remote code execution without requiring user interaction beyond visiting a malicious website. Attackers can craft specially designed web pages that trigger the WebGL fragment shader deletion sequence, leading to memory corruption that can be exploited to execute arbitrary code with the privileges of the browser process. This allows for complete system compromise, data theft, or further attack escalation. The vulnerability affects not just Firefox but also Thunderbird and SeaMonkey, expanding the potential attack surface significantly across Mozilla's ecosystem.
This vulnerability maps directly to CWE-416, which specifically addresses use-after-free conditions in memory management, and aligns with ATT&CK technique T1059.007 for command and scripting interpreter. The exploitation process typically involves leveraging the graphics rendering context to manipulate memory pointers, creating a scenario where freed memory can be reallocated and controlled by an attacker. Security researchers have noted that this class of vulnerability is particularly challenging to detect and prevent due to the complex nature of graphics API interactions and the timing dependencies involved in memory management operations. Organizations should prioritize immediate patching of affected versions and implement additional security measures such as sandboxing and memory protection mechanisms to mitigate the risk of exploitation.
The remediation approach for CVE-2012-3968 requires updating to patched versions of affected software, with Mozilla releasing updates for Firefox 15.0, Thunderbird 15.0, and SeaMonkey 2.12. Additionally, browser hardening techniques such as Address Space Layout Randomization, Data Execution Prevention, and Content Security Policy implementation can provide additional layers of protection against exploitation attempts. Security teams should also monitor for related vulnerabilities in WebGL implementations and maintain updated threat intelligence feeds to detect potential exploitation attempts.