USN-5111-2: strongSwan vulnerability

USN-5111-2: strongSwan vulnerability

USN-5111-1 fixed a vulnerability in strongSwan. This update provides
the corresponding update for Ubuntu 14.04 ESM and Ubuntu 16.04 ESM.

Original advisory details:

It was discovered that strongSwan incorrectly handled replacing
certificates in the cache. A remote attacker could use this issue to cause
strongSwan to crash, resulting in a denial of service, or possibly execute
arbitrary code. (CVE-2021-41991)
Source: USN-5111-2: strongSwan vulnerability