CVE-2013-0761 in Firefox
Summary
by MITRE
Use-after-free vulnerability in the mozilla::TrackUnionStream::EndTrack implementation in Mozilla Firefox before 18.0, Firefox ESR 17.x before 17.0.1, Thunderbird before 17.0.2, Thunderbird ESR 17.x before 17.0.1, and SeaMonkey before 2.15 allows remote attackers to execute arbitrary code or cause a denial of service (heap memory corruption) via unspecified vectors.
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Analysis
by VulDB Data Team • 04/20/2021
This vulnerability represents a critical use-after-free condition within Mozilla's media streaming implementation that affects multiple browser and email applications. The flaw exists in the mozilla::TrackUnionStream::EndTrack method which handles the termination of media tracks during streaming operations. When a media track is ended, the system attempts to free memory resources that may still be referenced elsewhere in the application's memory space, creating a scenario where subsequent memory access operations can trigger undefined behavior. The vulnerability stems from improper memory management where the system fails to properly track references to objects that are scheduled for deallocation, allowing attackers to manipulate the timing and execution flow to exploit this condition.
The technical implementation of this vulnerability involves heap memory corruption that occurs when the EndTrack function processes media stream termination. Attackers can craft malicious media content or web pages that trigger the specific code path leading to the use-after-free condition. The vulnerability is particularly dangerous because it can be exploited through web-based attacks without requiring user interaction beyond visiting a malicious website. The flaw demonstrates characteristics consistent with CWE-416, which describes the use of freed memory condition, and aligns with ATT&CK technique T1203, which involves exploiting software vulnerabilities to gain code execution capabilities. The memory corruption can manifest as either arbitrary code execution or denial of service depending on how the corrupted memory is subsequently accessed by the application.
The operational impact of this vulnerability extends across multiple Mozilla products including Firefox, Thunderbird, and SeaMonkey browsers, affecting users who may encounter malicious media content in web pages, email attachments, or streaming media. The vulnerability's exploitation potential makes it particularly concerning for enterprise environments where users may inadvertently access compromised content. Attackers can leverage this condition to execute malicious code with the privileges of the affected application, potentially leading to full system compromise. The widespread impact is amplified by the fact that these applications are commonly used for web browsing and email operations, making the attack surface extensive. Organizations running affected versions of these applications face significant risk of exploitation, particularly in environments where users have access to untrusted web content.
Mitigation strategies should focus on immediate patch deployment for all affected versions, as this vulnerability was addressed through memory management improvements in the patched releases. System administrators should prioritize updating to Firefox 18.0, Thunderbird 17.0.2, and SeaMonkey 2.15 or later versions. Additionally, implementing content filtering solutions and restricting access to untrusted media content can provide temporary protection while patches are deployed. Network-based security controls such as web application firewalls and intrusion prevention systems can help detect and block exploitation attempts. Regular security monitoring and vulnerability assessment programs should be implemented to identify and remediate similar memory corruption vulnerabilities. The fix typically involves proper reference counting and memory lifecycle management to ensure that objects are not freed while still being referenced, addressing the root cause of the use-after-free condition.