CVE-2015-2739 in Firefox
Summary
by MITRE
The ArrayBufferBuilder::append function in Mozilla Firefox before 39.0, Firefox ESR 31.x before 31.8 and 38.x before 38.1, and Thunderbird before 38.1 accesses unintended memory locations, which has unspecified impact and attack vectors.
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Analysis
by VulDB Data Team • 10/22/2024
The ArrayBufferBuilder::append function vulnerability in Mozilla Firefox represents a critical memory safety issue that affects multiple browser versions and the Thunderbird email client. This flaw exists within the core memory management mechanisms of the browser's JavaScript engine, specifically in how it handles array buffer operations. The vulnerability stems from improper bounds checking during memory allocation and data appending processes, allowing attackers to potentially access memory locations outside the intended buffer boundaries. The unspecified impact and attack vectors make this particularly concerning as it could enable various forms of memory corruption attacks.
The technical implementation of this vulnerability lies in the ArrayBufferBuilder::append function which is responsible for managing dynamic memory allocation for JavaScript array buffers. When processing data append operations, the function fails to properly validate memory boundaries, creating opportunities for out-of-bounds memory access. This type of flaw falls under the CWE-129 category of Improper Validation of Array Index, which is a common vector for memory corruption exploits. The vulnerability can be exploited through malicious web content that triggers the problematic append operation, potentially leading to arbitrary code execution or information disclosure.
The operational impact of CVE-2015-2739 extends beyond simple memory access violations, as it creates potential pathways for attackers to manipulate browser memory layouts. Attackers could leverage this vulnerability to execute code within the browser context, potentially leading to full system compromise when combined with other exploit techniques. The vulnerability affects not only regular Firefox users but also those using Firefox ESR (Extended Support Release) versions, which are typically deployed in enterprise environments where security is paramount. The fact that this vulnerability impacts Thunderbird as well indicates the widespread nature of the underlying memory management flaw within the Gecko rendering engine.
Mitigation strategies for this vulnerability require immediate patching of affected browser versions, with administrators prioritizing updates to Firefox 39.0, Thunderbird 38.1, and the corresponding ESR releases. Organizations should implement network-level protections such as content filtering and web application firewalls to reduce exposure to malicious content that might trigger this vulnerability. Security teams should also consider deploying exploit prevention mechanisms and monitoring for unusual memory access patterns that could indicate exploitation attempts. The vulnerability's classification under ATT&CK technique T1059.007 (Command and Scripting Interpreter: JavaScript) highlights the need for JavaScript execution monitoring and sandboxing controls. Additionally, browser hardening measures including disabling unnecessary JavaScript features and implementing strict content security policies can reduce the attack surface. Organizations should also maintain comprehensive incident response plans that account for potential memory corruption exploits, as the unspecified nature of this vulnerability's impact makes it particularly challenging to defend against without proper patch management and security monitoring procedures in place.