A strongSwan security update has been released for Ubuntu Linux 18.04 LTS, 20.04 LTS, and 21.10.

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Ubuntu Security Notice USN-5250-1
January 24, 2022

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

- Ubuntu 21.10
- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS

Summary:

strongSwan could crash or allow unintended access to network services.

Software Description:
- strongswan: IPsec VPN solution

Details:

Zhuowei Zhang discovered that stringSwan incorrectly handled EAP
authentication. A remote attacker could use this issue to cause strongSwan
to crash, resulting in a denial of service, or possibly bypass client and
server authentication.

Update instructions:

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

Ubuntu 21.10:
libstrongswan 5.9.1-1ubuntu3.2
strongswan 5.9.1-1ubuntu3.2

Ubuntu 20.04 LTS:
libstrongswan 5.8.2-1ubuntu3.4
strongswan 5.8.2-1ubuntu3.4

Ubuntu 18.04 LTS:
libstrongswan 5.6.2-1ubuntu2.8
strongswan 5.6.2-1ubuntu2.8

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

References:
  https://ubuntu.com/security/notices/USN-5250-1
CVE-2021-45079

Package Information:
  https://launchpad.net/ubuntu/+source/strongswan/5.9.1-1ubuntu3.2
  https://launchpad.net/ubuntu/+source/strongswan/5.8.2-1ubuntu3.4
  https://launchpad.net/ubuntu/+source/strongswan/5.6.2-1ubuntu2.8