========================================================================= Ubuntu Security Notice USN-4967-2 May 27, 2021 nginx vulnerability ========================================================================= A security issue affects these releases of Ubuntu and its derivatives: - Ubuntu 16.04 ESM - Ubuntu 14.04 ESM Summary: nginx could be made to crash or run programs if it received specially crafted network traffic. Software Description: - nginx: small, powerful, scalable web/proxy server Details: USN-4967-1 fixed a vulnerability in nginx. This update provides the corresponding update for Ubuntu 14.04 ESM and 16.04 ESM. Original advisory details: Luis Merino, Markus Vervier, and Eric Sesterhenn discovered that nginx incorrectly handled responses to the DNS resolver. A remote attacker could use this issue to cause nginx 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: nginx 1.10.3-0ubuntu0.16.04.5+esm1 nginx-common 1.10.3-0ubuntu0.16.04.5+esm1 nginx-core 1.10.3-0ubuntu0.16.04.5+esm1 nginx-extras 1.10.3-0ubuntu0.16.04.5+esm1 nginx-full 1.10.3-0ubuntu0.16.04.5+esm1 nginx-light 1.10.3-0ubuntu0.16.04.5+esm1 Ubuntu 14.04 ESM: nginx 1.4.6-1ubuntu3.9+esm2 nginx-common 1.4.6-1ubuntu3.9+esm2 nginx-core 1.4.6-1ubuntu3.9+esm2 nginx-extras 1.4.6-1ubuntu3.9+esm2 nginx-full 1.4.6-1ubuntu3.9+esm2 nginx-light 1.4.6-1ubuntu3.9+esm2 In general, a standard system update will make all the necessary changes. References: https://ubuntu.com/security/notices/USN-4967-2 https://ubuntu.com/security/notices/USN-4967-1 CVE-2021-23017