CVE-2016-2812 in Firefox
Summary
by MITRE
Race condition in the get implementation in the ServiceWorkerManager class in the Service Worker subsystem in Mozilla Firefox before 46.0 allows remote attackers to execute arbitrary code or cause a denial of service (buffer overflow and application crash) via a crafted web site.
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Analysis
by VulDB Data Team • 07/27/2022
The vulnerability identified as CVE-2016-2812 represents a critical race condition flaw within Mozilla Firefox's Service Worker subsystem, specifically affecting the ServiceWorkerManager class implementation. This issue exists in versions prior to Firefox 46.0 and exposes the browser to significant security risks that can be exploited remotely through malicious web content. The race condition manifests in the get implementation of the ServiceWorkerManager class, creating a scenario where concurrent operations can lead to unpredictable behavior and system instability.
The technical exploitation of this vulnerability occurs through a carefully crafted web page that triggers the race condition during Service Worker operations. When multiple threads attempt to access or modify shared resources within the ServiceWorkerManager class simultaneously, the lack of proper synchronization mechanisms allows for memory corruption to occur. This memory corruption can manifest as buffer overflows that ultimately result in arbitrary code execution or application crashes. The flaw is particularly dangerous because it operates at the core browser subsystem level, potentially allowing attackers to bypass traditional security measures and gain unauthorized access to system resources.
From an operational perspective, this vulnerability presents a severe threat to user security and system stability. The remote exploitation capability means that users can be compromised simply by visiting malicious websites, making this attack vector particularly insidious. The potential for both arbitrary code execution and denial of service creates a dual threat landscape where attackers can either take control of affected systems or disrupt normal browser operations. The buffer overflow conditions can be leveraged to execute malicious payloads with the privileges of the browser process, potentially leading to complete system compromise. This vulnerability directly impacts the browser's ability to maintain secure and stable operation, affecting millions of users who rely on Firefox for their web browsing needs.
The mitigation strategy for CVE-2016-2812 primarily involves upgrading to Firefox version 46.0 or later, where the race condition has been addressed through proper synchronization mechanisms and memory management improvements. Organizations should implement immediate patch management procedures to ensure all affected systems receive the necessary updates. Additionally, browser hardening measures such as enabling sandboxing features and restricting Service Worker permissions can provide additional layers of protection. Security monitoring should include detection of unusual Service Worker activity patterns that might indicate exploitation attempts. This vulnerability aligns with CWE-362, which specifically addresses race conditions, and represents a classic example of how improper synchronization can lead to critical security flaws in concurrent programming environments. The ATT&CK framework categorizes this vulnerability under privilege escalation and execution techniques, as attackers can leverage the race condition to execute arbitrary code with elevated privileges. Organizations should also consider implementing web filtering solutions and user education programs to reduce exposure to malicious websites that might exploit this vulnerability. Regular security assessments and penetration testing should include verification of Service Worker implementations to ensure proper mitigation of similar race condition vulnerabilities.