Cyber Resilience

CVE-2021-20314

Critical

Published: 12 August 2021

Published
12 August 2021
Modified
21 November 2024
KEV Added
—
Patch
—
CVSS Score v3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0017 37.9th percentile
Risk Priority 20 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-20314 is a critical-severity Out-of-bounds Write (CWE-787) vulnerability in Fedoraproject Fedora. Its CVSS base score is 9.8 (Critical).

Operationally, ranked at the 37.9th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

Stack buffer overflow in libspf2 versions below 1.2.11 when processing certain SPF macros can lead to Denial of service and potentially code execution via malicious crafted SPF explanation messages.

CWE(s)
CWE-787

Related Threats

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

Affected Assets

libspf2
libspf2
≤ 1.2.11
redhat
enterprise linux
7.0
fedoraproject
fedora
33, 34, 35

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.

SI-16 Memory Protection
addresses: CWE-787

Out-of-bounds writes that corrupt control flow or inject shellcode are rendered non-executable by the same memory protections.

References