CVE-2010-0165 in Firefox
Summary
by MITRE
The TraceRecorder::traverseScopeChain function in js/src/jstracer.cpp in the browser engine in Mozilla Firefox 3.6 before 3.6.2 allows remote attackers to cause a denial of service (memory corruption and application crash) and possibly execute arbitrary code via vectors involving certain indirect calls to the JavaScript eval function.
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Analysis
by VulDB Data Team • 05/03/2026
The vulnerability identified as CVE-2010-0165 represents a critical memory corruption flaw within the JavaScript engine of Mozilla Firefox 3.6 versions prior to 3.6.2. This issue resides in the TraceRecorder::traverseScopeChain function located in js/src/jstracer.cpp, which is part of the browser engine's Just-In-Time compilation system. The vulnerability manifests when the JavaScript engine processes certain indirect calls to the eval function, creating a scenario where malicious code can manipulate the execution flow and corrupt memory structures. The flaw specifically impacts the trace recording mechanism that is used to optimize JavaScript execution, making it particularly dangerous as it operates within the core engine components responsible for dynamic code execution.
The technical exploitation of this vulnerability occurs through the manipulation of JavaScript scope chains during trace recording operations. When indirect eval calls are processed, the TraceRecorder attempts to traverse the scope chain to determine variable access patterns for optimization purposes. However, the function fails to properly validate or handle certain edge cases in scope chain traversal, leading to memory corruption. This memory corruption can result in application crashes due to invalid memory access patterns, or in more severe cases, allow attackers to execute arbitrary code through controlled memory corruption. The vulnerability is classified under CWE-121 as a stack-based buffer overflow, though the actual mechanism involves heap corruption through improper scope chain handling. The flaw demonstrates characteristics consistent with the ATT&CK technique T1059.007 for JavaScript execution and T1499.004 for denial of service through memory corruption.
The operational impact of CVE-2010-0165 extends beyond simple application instability to potentially enable remote code execution in vulnerable environments. Attackers can craft malicious web pages that, when loaded in affected Firefox versions, trigger the vulnerable code path through indirect eval calls. This creates a vector where users can be exploited without requiring any special privileges or user interaction beyond visiting a malicious website. The memory corruption affects the JavaScript engine's internal data structures, potentially allowing attackers to overwrite critical memory regions or manipulate execution flow. The vulnerability is particularly concerning because it affects the core JavaScript engine components that are active during normal browsing operations, making it difficult to prevent through user behavior modifications alone.
Mitigation strategies for CVE-2010-0165 primarily involve immediate patching of affected Firefox installations to version 3.6.2 or later, which contains the necessary fixes for the scope chain traversal logic. Organizations should implement comprehensive browser update policies and consider deploying automated patch management systems to ensure rapid remediation across all affected systems. Network-level protections such as web application firewalls can provide additional layers of defense by monitoring for suspicious JavaScript patterns, though these are not foolproof given the nature of the vulnerability. Browser hardening techniques including disabling JavaScript when not required, using sandboxing mechanisms, and implementing content security policies can reduce the attack surface. Security teams should also monitor for exploitation attempts through intrusion detection systems, as the vulnerability manifests through characteristic memory access patterns that can be detected in network traffic or system logs. Regular security assessments of browser configurations and monitoring of threat intelligence feeds are recommended to identify potential exploitation attempts targeting this vulnerability.