CVE-2020-6389 in Chrome
Summary
by MITRE
Out of bounds write in WebRTC in Google Chrome prior to 80.0.3987.87 allowed a remote attacker to potentially exploit heap corruption via a crafted video stream.
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Analysis
by VulDB Data Team • 05/10/2025
The vulnerability CVE-2020-6389 represents a critical heap corruption issue within the WebRTC implementation of Google Chrome browsers prior to version 80.0.3987.87. This flaw exists in the handling of video streams and allows remote attackers to execute out-of-bounds write operations that can lead to memory corruption. The vulnerability specifically affects the WebRTC component responsible for real-time communication and media processing, making it particularly dangerous in environments where browsers handle untrusted video content from remote sources.
The technical root cause of this vulnerability stems from insufficient bounds checking within the WebRTC video processing pipeline. When Chrome receives a crafted video stream, the application fails to properly validate the size and structure of incoming video data before writing to memory buffers. This allows an attacker to manipulate the video stream in such a way that causes the application to write data beyond the allocated memory boundaries. The flaw manifests as an out-of-bounds write condition that can overwrite adjacent memory locations, potentially corrupting critical application data structures or even enabling arbitrary code execution. According to CWE classification, this vulnerability maps to CWE-787: Out-of-bounds Write, which is a well-documented weakness in software systems where programs write to memory locations outside the bounds of allocated buffers.
The operational impact of CVE-2020-6389 extends beyond simple memory corruption, as it creates a potential attack vector for remote code execution in the context of the browser. Attackers can leverage this vulnerability by crafting malicious video streams that, when processed by the affected Chrome versions, trigger the heap corruption. This makes the vulnerability particularly dangerous in web-based attack scenarios where users might encounter compromised video content through various channels including malicious websites, social engineering campaigns, or compromised advertising networks. The vulnerability affects users who are browsing the web and interacting with video content, making it a widespread concern for both individual users and enterprise environments that rely on Chrome for web browsing.
Security professionals should note that this vulnerability aligns with several techniques documented in the MITRE ATT&CK framework, particularly in the context of initial access and execution phases. The attack pattern follows ATT&CK technique T1203: Exploitation for Client Execution, where attackers exploit software vulnerabilities to execute code on target systems. The vulnerability also relates to T1059: Command and Scripting Interpreter, as successful exploitation could lead to command execution within the browser context. Organizations should prioritize patch management to ensure all Chrome installations are updated to version 80.0.3987.87 or later, as this represents the first version that contains the necessary fixes for the heap corruption issue. Additionally, network administrators should consider implementing web filtering solutions that can block access to known malicious domains that might serve such crafted video streams, providing an additional layer of defense against exploitation attempts.
The remediation strategy for CVE-2020-6389 primarily involves immediate deployment of Chrome version 80.0.3987.87 or higher across all affected systems. Organizations should also implement proactive monitoring for any indicators of exploitation attempts and maintain updated threat intelligence feeds to identify potential attack vectors. Security teams should conduct vulnerability assessments to identify systems running older Chrome versions and prioritize their remediation. The fix implemented by Google addresses the core bounds checking issue in the WebRTC video processing component, ensuring that all incoming video data is properly validated before memory allocation occurs. This vulnerability serves as a reminder of the critical importance of keeping browser software updated, as WebRTC implementations often handle complex multimedia processing that can introduce attack surface vulnerabilities when not properly secured against buffer overflow conditions.