=========================================================================Ubuntu Security Notice USN-5550-1
August 04, 2022

gnutls28 vulnerabilities
=========================================================================
A security issue affects these releases of Ubuntu and its derivatives:

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

Summary:

Several security issues were fixed in GnuTLS.

Software Description:
- gnutls28: GNU TLS library

Details:

It was discovered that GnuTLS incorrectly handled certain memory
operations. A remote attacker could possibly use this issue to cause GnuTLS
to crash, resulting in a denial of service. This issue only affected Ubuntu
18.04 LTS, and Ubuntu 20.04 LTS. (CVE-2021-4209)

It was discovered that GnuTLS incorrectly handled the verification of
certain pkcs7 signatures. A remote attacker could use this issue to cause
GnuTLS to crash, resulting in a denial of service, or possibly execute
arbitrary code. (CVE-2022-2509)

Update instructions:

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

Ubuntu 22.04 LTS:
  libgnutls30                     3.7.3-4ubuntu1.1

Ubuntu 20.04 LTS:
  libgnutls30                     3.6.13-2ubuntu1.7

Ubuntu 18.04 LTS:
  libgnutls30                     3.5.18-1ubuntu1.6

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

References:
  https://ubuntu.com/security/notices/USN-5550-1
  CVE-2021-4209, CVE-2022-2509

Package Information:
  https://launchpad.net/ubuntu/+source/gnutls28/3.7.3-4ubuntu1.1
  https://launchpad.net/ubuntu/+source/gnutls28/3.6.13-2ubuntu1.7
  https://launchpad.net/ubuntu/+source/gnutls28/3.5.18-1ubuntu1.6