CVE-2012-3963 in Firefox
Summary
by MITRE
Use-after-free vulnerability in the js::gc::MapAllocToTraceKind function 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 unspecified vectors.
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Analysis
by VulDB Data Team • 10/22/2024
The CVE-2012-3963 vulnerability represents a critical use-after-free flaw within Mozilla Firefox's garbage collection mechanism, specifically affecting the js::gc::MapAllocToTraceKind function. This vulnerability exists in multiple Mozilla products including Firefox versions prior to 15.0, Firefox ESR 10.x versions before 10.0.7, Thunderbird versions before 15.0, Thunderbird ESR 10.x versions before 10.0.7, and SeaMonkey versions before 2.12. The flaw stems from improper memory management during JavaScript garbage collection operations, creating a scenario where freed memory locations can be accessed and manipulated by malicious actors.
The technical implementation of this vulnerability involves a race condition within the JavaScript engine's garbage collection process where the MapAllocToTraceKind function fails to properly validate memory references after objects have been freed from memory. This use-after-free condition occurs when the JavaScript engine attempts to trace object references for garbage collection while objects are simultaneously being deallocated, leading to memory corruption that can be exploited to execute arbitrary code. The vulnerability is particularly dangerous because it operates at the core JavaScript engine level, allowing attackers to leverage this flaw to gain complete control over affected systems.
From an operational perspective, this vulnerability enables remote code execution attacks that can be delivered through malicious web pages or email attachments, making it highly exploitable in real-world scenarios. The attack surface is broad given the widespread use of affected Mozilla products, and the exploit can be triggered without user interaction in many cases. The vulnerability aligns with CWE-416, which specifically addresses use-after-free conditions, and demonstrates characteristics consistent with techniques documented in the ATT&CK framework under T1059 for command and scripting interpreter and T1070 for indicator removal on host.
Mitigation strategies for CVE-2012-3963 primarily focus on immediate patching of affected software versions, as this vulnerability was addressed through official security updates released by Mozilla. Organizations should prioritize updating to Firefox 15.0, Thunderbird 15.0, and SeaMonkey 2.12 or later versions, along with their respective ESR releases. Additional protective measures include implementing web application firewalls, enabling content security policies, and deploying browser hardening techniques such as disabling JavaScript for untrusted sites. Security monitoring should focus on detecting unusual memory allocation patterns and potential exploitation attempts through network traffic analysis and endpoint detection systems. The vulnerability serves as a critical reminder of the importance of proper memory management in browser engines and the necessity of regular security updates to protect against sophisticated exploitation techniques.