Researchers at Qualys have revealed three security vulnerabilities in a component of systemd. This is believed to be affecting almost all of the systemd based Linux distros. The silver lining is that most of the distros have been made aware of the issue and have been working on fixes for these exploits.
The patches are respectively CVE-2018-16864, CVE-2018-16865, and CVE-201819866. They should be appearing in repos soon. This has been attributed to coordinated disclosure by Qualys. Debian will remain vulnerable for the time being, however, according to The Register, Qualys’s Jimmy Graham has said “that they are aware of the issue and we should be seeing a fix soon.”
The bugs were found in system-journald, a component of system that handles the collection and storage of logs. The first two, CVE-2018-16864 and CVE-201816865, are memory corruption flaws. CVE-2018-16864 can be leveraged by malware to crash and potentially hijack the system-journald service, there-by elevating access from a user to root for the attacker. CVE-2018-16865 and CVE2018-16866 can be used together to crash or hijack a root privileged journal service by a local attacker.
These exploits are believed to affect almost all of the systemd based Linux distros in use today. However, SUSE Linux Enterprise, openSUSE Leap 15.0, and Fedora 28 & 29 do not seem to be affected. This is thought to be due to their user-land code being compiled with GCC’s –fstack-clash-protection.
CVE-2018-16864 entered into the code base in April of 2013, then became exploitable with system v203 in Feb 2016. CVE-2018-16865 seems to have appeared in the code base in 2011 in system v38 and became exploitable in April 2013 (systremd v 201). CVE-2018-16866 was introduced in June of 2015. However, it was inadvertently fixed in August of 2018.