Arch Linux Security Advisory ASA-201710-28 ========================================== Severity: Critical Date : 2017-10-21 CVE-ID : CVE-2017-15650 Package : musl Type : arbitrary code execution Remote : Yes Link : https://security.archlinux.org/AVG-457 Summary ======= The package musl before version 1.1.17-1 is vulnerable to arbitrary code execution. Resolution ========== Upgrade to 1.1.17-1. # pacman -Syu "musl>=1.1.17-1" The problem has been fixed upstream in version 1.1.17. Workaround ========== Using a local, trusted DNS resolver mitigates the issue. Description =========== A stack-based buffer overflow has been found in the DNS response parsing code of musl libc <= 1.1.16. When an application makes a request via getaddrinfo for both IPv4 and IPv6 results (AF_UNSPEC), an attacker who controls or can spoof the nameservers configured in resolv.conf can reply to both the A and AAAA queries with A results. Since A records are smaller than AAAA records, it's possible to fit more addresses than the precomputed bound, and a buffer overflow occurs. Impact ====== A remote attacker who controls or can spoof the nameservers configured in resolv.conf can execute arbitrary code on the affected host. References ========== http://seclists.org/oss-sec/2017/q4/107 https://git.musl-libc.org/cgit/musl/commit/?id=45ca5d3fcb6f874bf5ba55d0e9651cef68515395 https://security.archlinux.org/CVE-2017-15650