CVE-2021-21126
Published: 09 February 2021
Summary
CVE-2021-21126 is a medium-severity Improper Input Validation (CWE-20) vulnerability in Google Chrome. Its CVSS base score is 6.5 (Medium).
Operationally, ranked in the top 4.2% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2021-8517
Vulnerability details
Insufficient policy enforcement in extensions in Google Chrome prior to 88.0.4324.96 allowed a remote attacker to bypass site isolation via a crafted Chrome Extension.
- CWE(s)
Related Threats
No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.
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.
Security testing and developer training directly verify and enforce proper input validation, reducing exploitability of injection and malformed-data weaknesses.
Security testing and evaluation at multiple SDLC stages directly detects missing or flawed input validation, with the required remediation process ensuring fixes are applied.
Directly implements checks on information inputs to reject invalid data before processing.
Spam protection mechanisms perform filtering and detection on inbound/outbound messages, directly compensating for missing or weak input validation of unsolicited content.