CVE-2021-21220
Memory Safety in Fedoraproject Fedora 32 … 34
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-2021-21220 is a high-severity Out-of-bounds Write (CWE-787) vulnerability in Fedoraproject Fedora. 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 0.6% 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.
The vulnerability is an out-of-bounds write issue (CWE-787) stemming from insufficient validation of untrusted input in the V8 JavaScript engine within Google Chrome versions prior to 89.0.4389.128. It affects the browser's handling of crafted web content and carries a CVSS 3.1 base score of 8.8.
A remote attacker can exploit the flaw by serving a malicious HTML page to a victim, triggering heap corruption that may allow arbitrary code execution with the privileges of the Chrome process. User interaction is required in the form of visiting the page, after which the attacker could achieve full confidentiality, integrity, and availability impact.
Chrome stable channel updates and distribution advisories such as the Fedora package announcement direct users to upgrade immediately to version 89.0.4389.128 or later to address the issue. Public exploit code demonstrating remote code execution via the V8 JIT component has been published on Packet Storm.
The associated Chromium bug tracker entry provides additional technical details for analysts reviewing patch diffs or memory safety improvements in V8.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2021-8611
Vulnerability Data
Insufficient validation of untrusted input in V8 in Google Chrome prior to 89.0.4389.128 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page.
- CWE(s)
- KEV Date Added
- 03 November 2021
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.