CVE-2016-1972 in Firefox
Summary
by MITRE
Race condition in libvpx in Mozilla Firefox before 45.0 on Windows might allow remote attackers to cause a denial of service (use-after-free) or possibly have unspecified other impact via unknown vectors.
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Analysis
by VulDB Data Team • 10/11/2024
The vulnerability identified as CVE-2016-1972 represents a critical race condition flaw within the libvpx library component utilized by Mozilla Firefox browsers running on Windows operating systems. This issue affects Firefox versions prior to 45.0 and stems from improper handling of concurrent operations within the video decoding subsystem. The race condition occurs when multiple threads attempt to access and modify shared memory resources without proper synchronization mechanisms, creating opportunities for unpredictable behavior and system instability.
The technical implementation of this vulnerability manifests through a use-after-free condition that can be triggered remotely by malicious actors. When Firefox processes video content using the libvpx library, the race condition allows attackers to manipulate memory allocation patterns and potentially execute arbitrary code or cause application crashes. This flaw specifically impacts the video decoding pipeline where concurrent access to video frame buffers and decoder state information creates opportunities for memory corruption. The vulnerability's classification as a race condition aligns with CWE-362, which describes concurrent execution using shared resources without proper synchronization, making it particularly dangerous in multi-threaded environments.
From an operational perspective, this vulnerability poses significant risks to Firefox users in environments where they might encounter malicious web content. The remote exploitation capability means that attackers can potentially compromise systems simply by delivering malicious video content through web browsers, without requiring user interaction beyond visiting compromised websites. The potential impacts extend beyond simple denial of service to include possible code execution and privilege escalation scenarios, depending on the specific exploitation vectors. This vulnerability directly relates to ATT&CK technique T1203, which covers legitimate programs that are used to gain access to a system, and T1059, involving command and scripting interpreters, as exploitation could lead to further system compromise.
The mitigation strategies for CVE-2016-1972 primarily involve upgrading to Firefox version 45.0 or later, which includes patches that address the race condition in the libvpx library. Organizations should also implement network-based protections such as web application firewalls and content filtering solutions to prevent access to known malicious sites. Browser hardening measures including disabling unnecessary plugins and restricting multimedia content processing can further reduce the attack surface. Additionally, security monitoring should focus on detecting unusual memory access patterns and potential exploitation attempts through network traffic analysis. System administrators should ensure timely patch deployment across all affected systems and maintain updated threat intelligence feeds to identify potential exploitation attempts targeting this vulnerability. The fix implemented by Mozilla addressed the underlying synchronization issues within the video decoding component, preventing the race condition that enabled the use-after-free scenario and restoring proper memory management practices in the affected library integration.