CVE-2012-2868 in Chrome
Summary
by MITRE
Race condition in Google Chrome before 21.0.1180.89 allows remote attackers to cause a denial of service or possibly have unspecified other impact via vectors involving improper interaction between worker processes and an XMLHttpRequest (aka XHR) object.
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Analysis
by VulDB Data Team • 03/27/2021
The vulnerability identified as CVE-2012-2868 represents a critical race condition flaw in Google Chrome versions prior to 21.0.1180.89 that fundamentally compromises the browser's process isolation mechanisms. This vulnerability specifically targets the interaction between worker processes and XMLHttpRequest objects, creating a scenario where concurrent operations can lead to unpredictable behavior and system instability. The race condition occurs when multiple processes attempt to access shared resources simultaneously without proper synchronization, allowing malicious actors to exploit temporal gaps in the browser's execution flow.
The technical implementation of this vulnerability leverages the improper handling of cross-process communication between background worker threads and the main browser thread that manages XMLHttpRequest operations. When a web page initiates an XMLHttpRequest from within a worker process, the browser must coordinate between different process boundaries to manage the request lifecycle. The flaw arises from insufficient locking mechanisms and improper state management during these cross-process transitions, creating opportunities for attackers to manipulate the timing and execution flow of these operations. This allows for the exploitation of memory corruption patterns and process manipulation that can result in browser crashes or more severe security implications.
From an operational impact perspective, this vulnerability enables remote attackers to execute denial of service attacks against Chrome browsers by causing browser crashes and rendering pages unusable. The potential for unspecified other impacts suggests that attackers might be able to leverage this race condition to escalate privileges or execute arbitrary code within the browser sandbox. The vulnerability's remote exploitability means that simply visiting a malicious website could trigger the race condition, making it particularly dangerous in real-world scenarios where users frequently browse untrusted content. The attack vector involves carefully crafted web pages that utilize worker threads and XMLHttpRequest operations to manipulate the browser's internal state during process transitions.
The mitigation strategies for CVE-2012-2868 primarily focus on updating to Chrome version 21.0.1180.89 or later, which includes proper synchronization mechanisms and improved process isolation controls. Browser vendors should implement additional security controls such as enhanced memory protection, stricter inter-process communication protocols, and improved race condition detection mechanisms. Organizations should also consider implementing network-level protections and monitoring for suspicious browser behavior patterns that might indicate exploitation attempts. This vulnerability aligns with CWE-362, which describes race conditions in concurrent systems, and maps to attack techniques in the MITRE ATT&CK framework related to privilege escalation and denial of service operations. The flaw demonstrates the critical importance of proper process isolation and synchronization in modern browser architectures, where multiple execution contexts must interact safely without compromising system integrity or user security.