Remote code execution via WebGL heap overflow
Published Dec 19, 2023 · Updated Feb 13, 2025
Heap buffer overflow in Mozilla Firefox before 121 and Firefox ESR and Thunderbird before 115.6 allows remote attackers to execute code. The WebGL DrawElementsInstanced path mishandles attacker-controlled draw input when the Mesa vmwgfx driver is active, causing an out-of-bounds heap write. A victim must render malicious WebGL content on a Linux system using that driver; successful exploitation escapes the sandbox and runs code.
Summary
What happened
Heap buffer overflow in Mozilla Firefox before 121 and Firefox ESR and Thunderbird before 115.6 allows remote attackers to execute code. The WebGL DrawElementsInstanced path mishandles attacker-controlled draw input when the Mesa vmwgfx driver is active, causing an out-of-bounds heap write. A victim must render malicious WebGL content on a Linux system using that driver; successful exploitation escapes the sandbox and runs code.
The record
- CVE
- CVE-2023-6856
- Published
- Dec 19, 2023
- Updated
- Feb 13, 2025
- Vendor
- Mozilla
- Product
- Firefox
- Classifications
- CWE-787, T1203
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Dec 19, 2023CVE publishedPublication date reported by the CVE source.
- Feb 13, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=unspecified <121
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
- WebGL DrawElementsInstanced proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo