Debian 11 strongSwan Critical EAP-TTLS Integer Overflow DoS Vuln DLA-4512-1

Kazuma Matsumoto discovered an integer overflow bug in the EAP-TTLS plugin
of strongSwan, an IKE/IPsec suite.

The EAP-TTLS plugin doesn't check the length field in the header of
attribute-value pairs (AVPs) tunneled in EAP-TTLS, which can cause an
integer underflow that may lead to a crash. An unauthenticated attacker
could exploit this for a DoS attack by sending a crafted message.


For Debian 11 bullseye, this problem has been fixed in version
5.9.1-1+deb11u6.

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 LTS security advisories, how to apply
these updates to your system and frequently asked questions can be
found at: https://wiki.debian.org/LTS