CVE-2015-0829 in Firefox
Summary
by MITRE
Buffer overflow in libstagefright in Mozilla Firefox before 36.0 allows remote attackers to execute arbitrary code via a crafted MP4 video that is improperly handled during playback.
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Analysis
by VulDB Data Team • 03/10/2022
The vulnerability identified as CVE-2015-0829 represents a critical buffer overflow flaw within Mozilla Firefox's libstagefright component, which is responsible for handling multimedia content including MP4 video files. This vulnerability affects Firefox versions prior to 36.0 and creates a remote code execution risk when users encounter specially crafted malicious MP4 videos during playback. The issue stems from insufficient input validation and memory management within the video decoding pipeline, specifically in how the libstagefright library processes malformed MP4 container structures. The buffer overflow occurs when the application attempts to write data beyond the allocated memory boundaries while parsing the video metadata, creating opportunities for attackers to inject and execute arbitrary code on affected systems. This vulnerability is particularly concerning because it leverages the browser's multimedia handling capabilities, which are frequently accessed through web pages, making exploitation relatively easy and widespread.
The technical implementation of this vulnerability involves the improper handling of MP4 video headers and metadata structures within the libstagefright library. When Firefox encounters an MP4 file, the library parses the container format to extract video and audio streams, but fails to properly validate the length fields in the MP4 atoms. Attackers can craft MP4 files with maliciously constructed atom sizes that cause the parsing routine to write beyond allocated buffer boundaries. This memory corruption can be exploited to overwrite critical program execution structures such as return addresses or function pointers, allowing attackers to redirect program flow and execute malicious code with the privileges of the browser process. The vulnerability is classified as a classic stack-based buffer overflow, which aligns with CWE-121 and CWE-122 categories related to insufficient buffer bounds checking. The attack vector requires only that a user visit a web page containing the malicious video, making it particularly dangerous for phishing campaigns and drive-by download attacks.
The operational impact of CVE-2015-0829 extends beyond simple remote code execution, as it represents a significant threat to browser security and user privacy. Successful exploitation can lead to complete system compromise, allowing attackers to install malware, steal sensitive data, or establish persistent backdoors. The vulnerability affects users across different operating systems since Firefox is available on Windows, macOS, and Linux platforms, making it a widespread concern for enterprise environments. Organizations that rely heavily on web-based applications and media content are particularly vulnerable, as the attack surface includes not just individual user machines but entire corporate networks. The vulnerability also aligns with ATT&CK techniques related to initial access through malicious content and privilege escalation through browser-based exploits. Security researchers have noted that this vulnerability was actively exploited in the wild during 2015, with proof-of-concept code demonstrating successful exploitation against vulnerable Firefox installations.
Mitigation strategies for CVE-2015-0829 primarily focus on immediate patching and browser updates, as the most effective solution is upgrading to Firefox 36.0 or later versions where the vulnerability has been addressed. Organizations should implement comprehensive patch management procedures to ensure all browsers are updated promptly, particularly in enterprise environments where automated deployment systems can help maintain security posture. Additional defensive measures include implementing web content filtering solutions that can identify and block suspicious MP4 files, disabling automatic media playback in browsers, and using browser security extensions that provide additional sandboxing. Network-level protections such as intrusion detection systems can be configured to monitor for known malicious MP4 file signatures, while user education programs should emphasize the importance of avoiding untrusted web content. The vulnerability also highlights the importance of maintaining up-to-date security practices and regular vulnerability assessments to identify similar issues in other multimedia libraries and browser components. Organizations should consider implementing application whitelisting policies that restrict execution of untrusted multimedia content, particularly in high-risk environments where security is paramount.