** DISPUTED ** Sudo through 1.8.29 allows local users to escalate to root
if they have write access to file descriptor 3 of the sudo process. This
occurs because of a race condition between determining a uid, and the
setresuid and openat system calls. The attacker can write "ALL ALL=(ALL)
NOPASSWD:ALL" to /proc/#####/fd/3 at a time when Sudo is prompting for a
password. NOTE: This has been disputed due to the way Linux /proc works. It
has been argued that writing to /proc/#####/fd/3 would only be viable if
you had permission to write to /etc/sudoers. Even with write permission to
/proc/#####/fd/3, it would not help you write to /etc/sudoers.
mdeslaurthis isn't an issue and was rejected by upstream
Source: sudo (LP Ubuntu Debian)
Ubuntu 12.04 ESM (Precise Pangolin):not-affected
Ubuntu 14.04 ESM (Trusty Tahr):not-affected
Ubuntu 16.04 LTS (Xenial Xerus):not-affected
Ubuntu 18.04 LTS (Bionic Beaver):not-affected
Ubuntu 19.10 (Eoan Ermine):not-affected
Ubuntu 20.04 (Focal Fossa):not-affected
More Information

Updated: 2020-03-18 22:54:27 UTC (commit 2ea7df7bd1e69e1e489978d2724a936eb3faa1b8)