.. / env

Star

• Shell
• SUID
• Sudo

Shell

It can be used to break out from restricted environments by spawning an interactive system shell.

• env /bin/sh

SUID

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 sh -p, omit the -p argument on systems like Debian (<= Stretch) that allow the default sh shell to run with SUID privileges.

• sudo sh -c 'cp $(which env) .; chmod +s ./env'
  
  ./env /bin/sh -p

Sudo

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.

• sudo env /bin/sh