CVE-2018-6129 in Chrome
Summary
by MITRE
Out of bounds array access in WebRTC in Google Chrome prior to 67.0.3396.62 allowed a remote attacker to potentially perform out of bounds memory access via a crafted HTML page.
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Analysis
by VulDB Data Team • 01/27/2025
The vulnerability identified as CVE-2018-6129 represents a critical out-of-bounds array access flaw within the WebRTC implementation of Google Chrome browsers. This issue affects versions prior to 67.0.3396.62 and stems from improper bounds checking during WebRTC media processing operations. The vulnerability manifests when a maliciously crafted HTML page is loaded in a vulnerable browser instance, creating a scenario where remote attackers can exploit memory access violations without requiring any user interaction beyond visiting the compromised webpage.
The technical root cause of this vulnerability lies in insufficient input validation within the WebRTC component's handling of array operations. When processing media streams or signaling data, the WebRTC implementation fails to properly validate array indices before accessing memory locations, allowing attackers to manipulate these indices beyond the allocated array boundaries. This type of flaw falls under the CWE-129 category of "Improper Validation of Array Index" and specifically aligns with the broader class of memory safety vulnerabilities that have been extensively documented in cybersecurity literature. The vulnerability's exploitation potential is significantly enhanced by the fact that WebRTC functionality is commonly enabled in modern browsers and frequently used in web applications, making it a prime target for remote code execution attempts.
The operational impact of CVE-2018-6129 extends beyond simple memory corruption, as it provides attackers with potential pathways for privilege escalation and system compromise. When an out-of-bounds memory access occurs, it can lead to arbitrary code execution, information disclosure, or denial of service conditions depending on the specific memory locations accessed and the attacker's objectives. The vulnerability's remote nature means that attackers can leverage this flaw through web-based attacks without requiring physical access to target systems, making it particularly dangerous in enterprise environments where users regularly browse untrusted websites. This vulnerability directly maps to several ATT&CK techniques including T1059 for command and scripting interpreter usage and T1068 for exploit for privilege escalation, as the initial compromise could lead to further system exploitation.
Mitigation strategies for CVE-2018-6129 primarily focus on immediate browser updates and implementation of additional security controls. Organizations should prioritize updating all affected Chrome installations to version 67.0.3396.62 or later, as this release contains the necessary patches to address the bounds checking deficiencies. Beyond patching, network administrators can implement browser security policies that restrict WebRTC functionality in high-risk environments or deploy web application firewalls that can detect and block malicious WebRTC-related traffic patterns. Additionally, security teams should monitor for exploitation attempts through network traffic analysis, as the vulnerability may manifest through unusual WebRTC signaling or media stream behaviors that can be detected by intrusion detection systems. The vulnerability also underscores the importance of maintaining comprehensive browser security configurations and implementing security awareness training to reduce the risk of users inadvertently visiting malicious websites that could exploit this and similar vulnerabilities.