Arch Linux Security Advisory ASA-201609-31 ========================================== Severity: High Date : 2016-09-30 CVE-ID : CVE-2016-5180 Package : c-ares Type : arbitrary code execution Remote : Yes Link : https://wiki.archlinux.org/index.php/CVE Summary ======= The package c-ares before version 1.12.0-1 is vulnerable to arbitrary code execution. Resolution ========== Upgrade to 1.12.0-1. # pacman -Syu "c-ares>=1.12.0-1" The problem has been fixed upstream in version 1.12.0. Workaround ========== None. Description =========== When a string is passed in to ares_create_query or ares_mkquery and uses an escaped trailing dot, like "hello\.", c-ares calculates the string length wrong and subsequently writes outside of the the allocated buffer with one byte. The wrongly written byte is the least significant byte of the 'dnsclass' argument; most commonly 1. Impact ====== A remote attacker is able to perform a denial of service attack or possibly execute arbitrary code under certain circumstances. References ========== https://c-ares.haxx.se/adv_20160929.html https://c-ares.haxx.se/CVE-2016-5180.patch https://access.redhat.com/security/cve/CVE-2016-5180