util-linux wall Escape Sequence Injection

The util-linux wall command does not filter escape sequences from command line arguments. The vulnerable code was introduced in commit cdd3cc7fa4 (2013). Every version since has been vulnerable. This allows unprivileged users to put arbitrary text on other users terminals, if mesg is set to y and wall is setgid. CentOS is not vulnerable since wall is not setgid. On Ubuntu 22.04 and Debian Bookworm, wall is both setgid and mesg is set to y by default.

centos code command command line commit escape filter injection line linux text version vulnerable wall