========================================================================== Ubuntu Security Notice USN-5168-4 December 07, 2021 nss regression ========================================================================== A security issue affects these releases of Ubuntu and its derivatives: - Ubuntu 16.04 ESM - Ubuntu 14.04 ESM Summary: USN-5168-3 introduced a regression in NSS. Software Description: - nss: Network Security Service library Details: USN-5168-3 fixed a vulnerability in NSS. Unfortunately that update introduced a regression that could break SSL connections. This update fixes the problem. We apologize for the inconvenience. Original advisory details: Tavis Ormandy discovered that NSS incorrectly handled verifying DSA/RSA-PSS signatures. A remote attacker could use this issue to cause NSS to crash, resulting in a denial of service, or possibly execute arbitrary code. Update instructions: The problem can be corrected by updating your system to the following package versions: Ubuntu 16.04 ESM: libnss3 2:3.28.4-0ubuntu0.16.04.14+esm2 Ubuntu 14.04 ESM: libnss3 2:3.28.4-0ubuntu0.14.04.5+esm10 After a standard system update you need to restart any applications that use NSS, such as Evolution, to make all the necessary changes. References: https://ubuntu.com/security/notices/USN-5168-4 https://ubuntu.com/security/notices/USN-5168-1 CVE-2021-43527