Cyber Resilience

CVE-2023-5981

Medium

Published: 28 November 2023

Published
28 November 2023
Modified
25 March 2026
KEV Added
Patch
CVSS Score v3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS Score 0.0084 75.2th percentile
Risk Priority 12 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2023-5981 is a medium-severity Observable Timing Discrepancy (CWE-208) vulnerability in Redhat Linux. Its CVSS base score is 5.9 (Medium).

Operationally, ranked in the top 24.8% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

A vulnerability was found that the response times to malformed ciphertexts in RSA-PSK ClientKeyExchange differ from response times of ciphertexts with correct PKCS#1 v1.5 padding.

CWE(s)

Related Threats

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

Affected Assets

debian
debian linux
10.0
gnu
gnutls
≤ 3.8.2
redhat
linux
8.0, 9.0
fedoraproject
fedora
37, 38

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-203 CWE-208

Misdirection can normalize or falsify responses to eliminate observable discrepancies that aid reconnaissance.

addresses: CWE-208 CWE-203

Observable timing discrepancies are a primary mechanism for constructing covert timing channels; analysis identifies and bounds them, limiting exploitation.

addresses: CWE-203

Prevents attackers from using observable differences in error responses to infer internal system details or state.

References