USN-4246-1: zlib vulnerabilities

22 January 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

To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.

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

References