Memory disclosure via unvalidated WebGL2 framebuffer blit
Published Nov 21, 2023 · Updated Feb 13, 2025
WebGL2 out-of-bounds read in affected Firefox and Thunderbird versions allows remote attackers to leak memory through canvas images. With KHR_no_error enabled, blitFramebuffer skips ANGLE format validation and passes mismatched depth-stencil formats into BlitD24S8ToD32F, which reads beyond the source buffer. A user must open attacker-controlled WebGL content on a graphics-and-driver combination that takes this path; Firefox before 120, Firefox ESR before 115.5.0, and Thunderbird before 115.5 are affected.
Summary
What happened
WebGL2 out-of-bounds read in affected Firefox and Thunderbird versions allows remote attackers to leak memory through canvas images. With KHR_no_error enabled, blitFramebuffer skips ANGLE format validation and passes mismatched depth-stencil formats into BlitD24S8ToD32F, which reads beyond the source buffer. A user must open attacker-controlled WebGL content on a graphics-and-driver combination that takes this path; Firefox before 120, Firefox ESR before 115.5.0, and Thunderbird before 115.5 are affected.
The record
- CVE
- CVE-2023-6204
- Published
- Nov 21, 2023
- Updated
- Feb 13, 2025
- Vendor
- Mozilla
- Product
- Firefox
- Classifications
- CWE-125, T1189
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Nov 21, 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
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=unspecified <120
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
- Bug 1841050 blit.html proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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