CVE-2015-6771 in Chrome
Summary
by MITRE
js/array.js in Google V8, as used in Google Chrome before 47.0.2526.73, improperly implements certain map and filter operations for arrays, which allows remote attackers to cause a denial of service (out-of-bounds memory access) or possibly have unspecified other impact via crafted JavaScript code.
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Analysis
by VulDB Data Team • 06/28/2022
The vulnerability identified as CVE-2015-6771 resides within the V8 JavaScript engine's implementation of array operations, specifically affecting Google Chrome versions prior to 47.0.2526.73. This flaw manifests in the js/array.js file where the map and filter functions are improperly handled, creating a critical security gap that can be exploited by remote attackers. The issue stems from inadequate bounds checking during array manipulation operations, allowing malicious JavaScript code to access memory locations outside the intended array boundaries.
The technical implementation flaw involves the improper handling of array indexing during map and filter operations within V8's JavaScript engine. When these functions process arrays with specific characteristics, the engine fails to validate array bounds properly, leading to out-of-bounds memory access patterns. This vulnerability operates at the intersection of multiple cybersecurity domains, with the underlying cause aligning with CWE-129, which addresses improper validation of array indices, and CWE-787, concerning out-of-bounds write operations. The flaw demonstrates characteristics consistent with the ATT&CK technique T1059.007, which involves the use of JavaScript for malicious purposes, particularly in web-based exploitation scenarios.
The operational impact of this vulnerability extends beyond simple denial of service conditions, as it can potentially enable more severe consequences including arbitrary code execution or information disclosure. Remote attackers can craft malicious JavaScript payloads that exploit the improper array handling to trigger memory corruption, leading to system instability or unauthorized access to sensitive data. The vulnerability's remote exploitability means that attackers can leverage it through web browsers without requiring local system access, making it particularly dangerous in enterprise environments where users may encounter malicious content through email attachments, web browsing, or compromised websites. The out-of-bounds memory access can result in crashes that disrupt user sessions, or more dangerously, allow attackers to execute arbitrary code with the privileges of the browser process.
Mitigation strategies for CVE-2015-6771 focus primarily on updating to patched versions of Google Chrome, specifically version 47.0.2526.73 or later where the array handling logic has been corrected. Organizations should implement comprehensive patch management procedures to ensure all systems running vulnerable versions of Chrome receive updates promptly. Additionally, browser security configurations can be enhanced through the implementation of Content Security Policies that limit the execution of potentially malicious scripts. Network-level protections such as web application firewalls and intrusion prevention systems can provide additional layers of defense by monitoring for suspicious JavaScript patterns. The vulnerability also underscores the importance of regular security assessments and code reviews for JavaScript engines, particularly focusing on memory safety mechanisms and array boundary validation. Organizations should consider implementing sandboxing technologies and privilege separation techniques to limit the potential damage from successful exploits, while also maintaining detailed monitoring and logging of browser activities to detect anomalous behavior indicative of exploitation attempts.