Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2023-6856 is a high-severity Out-of-bounds Write (CWE-787) vulnerability in Debian Debian Linux. Its CVSS base score is 8.8 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Security Account Manager (T1003.002); ranked in the top 3% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
The WebGL DrawElementsInstanced method was susceptible to a heap buffer overflow when used on systems with the Mesa VM driver. This vulnerability affects Firefox ESR versions prior to 115.6, Thunderbird versions prior to 115.6, and Firefox versions prior to 121, and carries a CVSS 3.1 score of 8.8 with the CWE-787 classification for out-of-bounds writes.
An attacker able to supply malicious WebGL content can trigger the overflow to achieve remote code execution and escape the browser sandbox on affected systems. Exploitation requires user interaction such as visiting a crafted page but needs no other privileges.
Debian, Gentoo, and Mozilla advisories direct users to apply the fixed releases listed in the referenced security announcements, including DSA-5581 and GLSA-202401-10, which address the issue through updated packages. The associated EPSS score reached a peak of 0.1237 with a current value of 0.1047.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2023-59060
Vulnerability Data
The WebGL `DrawElementsInstanced` method was susceptible to a heap buffer overflow when used on systems with the Mesa VM driver. This issue could allow an attacker to perform remote code execution and sandbox escape. This vulnerability affects Firefox ESR <…
more
115.6, Thunderbird < 115.6, and Firefox < 121.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Out-of-bounds writes that corrupt control flow or inject shellcode are rendered non-executable by the same memory protections.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Vulnerability scanning and recording can discover out-of-bounds write flaws so they can be remediated.
Patching or replacing vulnerable software directly eliminates known instances of this coding weakness.
Secure-development practices (static analysis, bounds checking, code review) are the primary means of preventing out-of-bounds writes.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.