CVE-2023-5217
Memory Safety in Mozilla Firefox ≤ 115.3.1
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-2023-5217 is a high-severity Out-of-bounds Write (CWE-787) vulnerability in Mozilla Firefox. 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 1% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog; a public proof-of-concept is referenced.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
A heap buffer overflow vulnerability exists in the VP8 encoding functionality of libvpx, affecting Google Chrome versions prior to 117.0.5938.132 as well as libvpx releases before 1.13.1. The flaw, assigned CWE-787, permits out-of-bounds writes that can corrupt heap memory when processing specially crafted input. It carries a CVSS 3.1 base score of 8.8 and was rated High severity by the Chromium project.
A remote attacker can trigger the issue by serving a crafted HTML page that causes the browser or any application using the vulnerable libvpx library to encode VP8 video. Successful exploitation may allow arbitrary code execution or other impacts affecting confidentiality, integrity, and availability, although user interaction is required to render the malicious page.
Public advisories on the referenced Openwall and Seclists lists confirm that the issue is resolved by updating Chrome to version 117.0.5938.132 or later and by upgrading libvpx to 1.13.1, which contains the corrected encoding logic.
The EPSS score for this CVE rose sharply from a low baseline to a peak of 0.7546 on 2025-01-02 before receding to the current value of 0.0498, indicating a period of heightened exploitation interest well after initial disclosure.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2023-2578
Vulnerability Data
Heap buffer overflow in vp8 encoding in libvpx in Google Chrome prior to 117.0.5938.132 and libvpx 1.13.1 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page. (Chromium security severity: High)
- CWE(s)
- KEV Date Added
- 02 October 2023
Related Threats
MITRE ATT&CK Enterprise Techniques
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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.