=========================================================================Ubuntu Security Notice USN-5330-1
March 15, 2022

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

- Ubuntu 21.10
- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS

Summary:

LibreOffice could incorrectly validate document signatures.

Software Description:
- libreoffice: Office productivity suite

Details:

It was discovered that LibreOffice incorrectly handled digital signatures.
An attacker could possibly use this issue to create a specially crafted
document that would display a validly signed indicator, contrary to
expectations.

Update instructions:

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

Ubuntu 21.10:
  libreoffice-core                1:7.2.5-0ubuntu0.21.10.3

Ubuntu 20.04 LTS:
  libreoffice-core                1:6.4.7-0ubuntu0.20.04.4

Ubuntu 18.04 LTS:
  libreoffice-core                1:6.0.7-0ubuntu0.18.04.11

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

References:
  https://ubuntu.com/security/notices/USN-5330-1
  CVE-2021-25636

Package Information:
  https://launchpad.net/ubuntu/+source/libreoffice/1:7.2.5-0ubuntu0.21.10.3
  https://launchpad.net/ubuntu/+source/libreoffice/1:6.4.7-0ubuntu0.20.04.4
  https://launchpad.net/ubuntu/+source/libreoffice/1:6.0.7-0ubuntu0.18.04.11