A strongSwan security update has been released for Ubuntu Linux 18.04 LTS, 20.04 LTS, and 22.04 LTS.

USN-5651-1: strongSwan vulnerability

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Ubuntu Security Notice USN-5651-1
October 03, 2022

strongswan vulnerability
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A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 22.04 LTS
- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS

Summary:

strongSwan could be made do denial of service if it received
a specially crafted certificate.

Software Description:
- strongswan: IPsec VPN solution

Details:

Lahav Schlesinger discovered that strongSwan incorrectly handled certain OCSP URIs and
and CRL distribution points (CDP) in certificates. A remote attacker could
possibly use this issue to initiate IKE_SAs and send crafted certificates
that contain URIs pointing to servers under their control, which can lead
to a denial-of-service attack.

Update instructions:

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 22.04 LTS:
libstrongswan 5.9.5-2ubuntu2.1
strongswan 5.9.5-2ubuntu2.1

Ubuntu 20.04 LTS:
libstrongswan 5.8.2-1ubuntu3.5
strongswan 5.8.2-1ubuntu3.5

Ubuntu 18.04 LTS:
libstrongswan 5.6.2-1ubuntu2.9
strongswan 5.6.2-1ubuntu2.9

In general, a standard system update will make all the necessary changes.

References:
  https://ubuntu.com/security/notices/USN-5651-1
CVE-2022-40617

Package Information:
  https://launchpad.net/ubuntu/+source/strongswan/5.9.5-2ubuntu2.1
  https://launchpad.net/ubuntu/+source/strongswan/5.8.2-1ubuntu3.5
  https://launchpad.net/ubuntu/+source/strongswan/5.6.2-1ubuntu2.9