CVE-2018-6552 Apport treats the container PID as the global PID when /proc/<global_pid>/ is missing

High 7.8 Published 31 May 2018 Updated 17 Sep 2024

Local attackers can exploit Apport's PID namespace handling to create root-owned files, leading to privilege escalation or container escape.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Local or same network only
Victim action needed: Not needed
Fix: Available

What is CVE-2018-6552?

CVE-2018-6552 is a high-severity vulnerability in Apport, published on 31 May 2018. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

Apport does not properly handle crashes originating from a PID namespace allowing local users to create certain files as root which an attacker could leverage to perform a denial of service via resource exhaustion, possibly gain root privileges, or escape from containers. The is_same_ns() function returns True when /proc/<global pid>/ does not exist in order to indicate that the crash should be handled in the global namespace rather than inside of a container. However, the portion of the data/apport code that decides whether or not to forward a crash to a container does not always replace sys.argv[1] with the value stored in the host_pid variable when /proc/<global pid>/ does not exist which results in the container pid being used in the global namespace. This flaw affects versions 2.20.8-0ubuntu4 through 2.20.9-0ubuntu7, 2.20.7-0ubuntu3.7, 2.20.7-0ubuntu3.8, 2.20.1-0ubuntu2.15 through 2.20.1-0ubuntu2.17, and 2.14.1-0ubuntu3.28.

Which versions are affected by CVE-2018-6552?

It affects 1 product.

Products include Apport Project Apport.

How do I fix CVE-2018-6552?

Apply the vendor's patch.

Is CVE-2018-6552 being exploited?

There is no known exploitation of CVE-2018-6552 in the wild and no public exploit code.

Sources

Also known as GHSA-4pgc-f487-53cr, UBUNTU-CVE-2018-6552, USN-3664-1, USN-3664-2.