========================================================================== Ubuntu Security Notice USN-4246-1 January 22, 2020 zlib vulnerabilities ========================================================================== A security issue affects these releases of Ubuntu and its derivatives: - Ubuntu 16.04 LTS Summary: Several security issues were fixed in zlib Software Description: - zlib: Lossless data-compression library Details: It was discovered that zlib incorrectly handled pointer arithmetic. An attacker could use this issue to cause zlib to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2016-9840, CVE-2016-9841) It was discovered that zlib incorrectly handled vectors involving left shifts of negative integers. An attacker could use this issue to cause zlib to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2016-9842) It was discovered that zlib incorrectly handled vectors involving big-endian CRC calculation. An attacker could use this issue to cause zlib to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2016-9843) Update instructions: The problem can be corrected by updating your system to the following package versions: Ubuntu 16.04 LTS: lib32z1 1:1.2.8.dfsg-2ubuntu4.3 lib64z1 1:1.2.8.dfsg-2ubuntu4.3 libn32z1 1:1.2.8.dfsg-2ubuntu4.3 libx32z1 1:1.2.8.dfsg-2ubuntu4.3 zlib1g 1:1.2.8.dfsg-2ubuntu4.3 In general, a standard system update will make all the necessary changes. References: https://usn.ubuntu.com/4246-1 CVE-2016-9840, CVE-2016-9841, CVE-2016-9842, CVE-2016-9843 Package Information: https://launchpad.net/ubuntu/+source/zlib/1:1.2.8.dfsg-2ubuntu4.3