CVE-2021-41991

medium
Published — · Modified —
CVSS v3
CVSS v2
VIR risk
5.5

Description

The in-memory certificate cache in strongSwan before 5.9.4 has a remote integer overflow upon receiving many requests with different certificates to fill the cache and later trigger the replacement of cache entries. The code attempts to select a less-often-used cache entry by means of a random number generator, but this is not done correctly. Remote code execution might be a slight possibility.

Predictions

Exploit likelihood
20%
Patch ETA

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

vendor Authored 2026-05-27

Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2021-41991

vendor Authored 2026-05-27

Vendor advisory: suse — https://www.suse.com/security/cve/CVE-2021-41991.html

OS impact

OSVersionStatusFixed in
arch archfixed5.9.4-1
suse slesaffected
debian debianbookwormfixed5.9.4-1
debian debianbullseyefixed5.9.1-1+deb11u1
debian debianforkyfixed5.9.4-1
debian debiansidfixed5.9.4-1
debian debiantrixiefixed5.9.4-1

References

Verify integrity in audit chain (admin only). AS-IS.