Sudo before 1.9.17p1, when used with a sudoers file that specifies a host that is neither the current host nor ALL, allows listed users to execute commands on unintended machines.
Sudo before 1.9.17p1 allows local users to obtain root access because /etc/nsswitch.conf from a user-controlled directory is used with the --chroot option.
Sudo before 1.9.15 might allow row hammer attacks (for authentication bypass or privilege escalation) because application logic sometimes is based on not equaling an error value (instead of equaling a success value), and because the values do not resist flips of a single bit.