Debian: DSA-5249-1 Urgent Resolution for StrongSwan DoS Vulnerability

The revocation plugin uses OCSP URIs and CRL distribution points (CDP) which
come from certificates provided by the remote endpoint. The plugin didn't check
for the certificate chain of trust before using those URIs, so an attacker
could provided a crafted certificate containing URIs pointing to servers under
their control, potentially leading to denial-of-service attacks.

For the stable distribution (bullseye), this problem has been fixed in
version 5.9.1-1+deb11u3.

We recommend that you upgrade your strongswan packages.

For the detailed security status of strongswan please refer to
its security tracker page at:
https://security-tracker.debian.org/tracker/source-package/strongswan

Further information about Debian Security Advisories, how to apply
these updates to your system and frequently asked questions can be
found at: https://www.debian.org/security/