Cyber Resilience

CVE-2021-3910

Medium

Published: 11 November 2021

Published
11 November 2021
Modified
15 April 2026
KEV Added
Patch
CVSS Score v3.1 4.4 CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0056 68.6th percentile
Risk Priority 9 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-3910 is a medium-severity Improper Input Validation (CWE-20) vulnerability in Cloudflare Octorpki. Its CVSS base score is 4.4 (Medium).

Operationally, ranked in the top 31.4% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

OctoRPKI crashes when encountering a repository that returns an invalid ROA (just an encoded NUL (\0) character).

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

cloudflare
octorpki
≤ 1.4.0
debian
debian linux
11.0

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.

addresses: CWE-20

Security testing and developer training directly verify and enforce proper input validation, reducing exploitability of injection and malformed-data weaknesses.

addresses: CWE-20

Security testing and evaluation at multiple SDLC stages directly detects missing or flawed input validation, with the required remediation process ensuring fixes are applied.

addresses: CWE-20

Directly implements checks on information inputs to reject invalid data before processing.

addresses: CWE-20

Spam protection mechanisms perform filtering and detection on inbound/outbound messages, directly compensating for missing or weak input validation of unsolicited content.

References