CVE-2021-30568 in Chrome
Summary
by MITRE • 08/04/2021
Heap buffer overflow in WebGL in Google Chrome prior to 92.0.4515.107 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page.
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Analysis
by VulDB Data Team • 08/07/2021
The vulnerability identified as CVE-2021-30568 represents a critical heap buffer overflow flaw within the WebGL implementation of Google Chrome browsers. This vulnerability affects versions prior to 92.0.4515.107 and exposes users to potential remote code execution risks through maliciously crafted web pages. The flaw resides in the graphics processing capabilities of the browser, specifically within the WebGL graphics API implementation that enables hardware-accelerated 3D graphics rendering in web applications.
The technical nature of this vulnerability stems from improper bounds checking during memory allocation and manipulation within the WebGL subsystem. When processing specially crafted HTML pages containing malicious WebGL content, the browser fails to properly validate input parameters and buffer sizes, leading to unauthorized memory access patterns that can overwrite adjacent heap memory regions. This heap corruption occurs during the execution of graphics rendering operations, where the browser allocates memory buffers for texture data, vertex attributes, and other graphics resources. The flaw manifests when the WebGL implementation attempts to handle malformed or oversized data structures that exceed allocated buffer boundaries, creating opportunities for attackers to manipulate memory layout and potentially execute arbitrary code.
The operational impact of this vulnerability extends beyond simple browser exploitation, as it represents a sophisticated attack vector that can be leveraged for advanced persistent threats. Attackers can craft HTML pages containing malicious WebGL code that, when loaded in vulnerable Chrome versions, triggers the buffer overflow condition. This allows for remote code execution with the privileges of the browser process, potentially enabling full system compromise. The vulnerability's exploitability is heightened by the fact that it requires no user interaction beyond visiting a malicious webpage, making it particularly dangerous in phishing campaigns or compromised websites. Security researchers have classified this issue as a high-severity vulnerability due to its remote exploitability and potential for privilege escalation.
Mitigation strategies for CVE-2021-30568 primarily focus on immediate browser updates to patched versions that address the heap buffer overflow conditions. Organizations should implement comprehensive patch management procedures to ensure all Chrome installations are updated to version 92.0.4515.107 or later, which contains the necessary memory validation fixes. Additional defensive measures include implementing web application firewalls that can detect and block suspicious WebGL content, enabling browser security features such as site isolation and sandboxing, and deploying network monitoring solutions to detect potential exploitation attempts. From a compliance perspective, this vulnerability aligns with CWE-121, which addresses stack and heap buffer overflow conditions, and maps to ATT&CK technique T1059.007 for browser-based command execution. Organizations should also consider implementing security awareness training to educate users about the risks of visiting untrusted websites and the importance of keeping browser software updated to protect against such sophisticated exploits.