CVE-2018-1121

procps-ng, procps is vulnerable to a process hiding through race condition.
Since the kernel’s proc_pid_readdir() returns PID entries in ascending
numeric order, a process occupying a high PID can use inotify events to
determine when the process list is being scanned, and fork/exec to obtain a
lower PID, thus avoiding enumeration. An unprivileged attacker can hide a
process from procps-ng’s utilities by exploiting a race condition in
reading /proc/PID entries. This vulnerability affects procps and procps-ng
up to version 3.3.15, newer versions might be affected also.

Notes