Apple Remote Desktop root vulneravility
Background:
ARD allows unix commands to be remotely sent from an admin workstation. These
commands can be run as root, because the ard administrator can be given sudo
access. This exploit involves sending a unix command as root to install a
package that was copied to /tmp/. In this case, the app is Adobe CS 2.0 using
the adobe silent installation script. The script will mount disk images as
root, run the install, then cleanup. If a standard user is logged in, they will
see an icon on the dock for the install, but should never see anything besides
the icon.
The issue:
The process LoginWindow is owned by the logged in user. If the system is at
the login window, then the process LoginWindow is owned by root. If the system
is mounting a disk image visible only to root, then the image will try to
appear on the desktop. Clicking the mouse will force the desktop to appear, as
well as the menus. A user sitting that the system will then see a finder
window, and the root users home directory. The login window can be ignored, and
the user has full root access. Files can be deleted without authentication, and
the trash can be emptied. If a user tries to login, the login window will check
their credentials, but they will end up logging in to the root desktop with
root privileges.
The workaround:
If you are trying to run a remote install script such as the Adobe Silent
installer, use the lock screen feature in ARD. This locks the users desktop
until the admin is done doing their thing.
The end result:
http://www.flickr.com/photos/metfoo/246858852/
Adobes script:
#!/bin/sh
#
# Example script to run the Adobe Creative Suite 2 Installer silently.
#
#
# Copyright: 2005 Adobe Systems, Inc.
#
#
function detach_images
{
# umount any previous mounted installer images
for NUMBER in 1 2 3 4
do
MOUNTED_POINT="/Volumes/Adobe Creative Suite Disk ${NUMBER} "
/sbin/mount |/usr/bin/grep "${MOUNTED_POINT}" 2>/dev/null
if [ $? -eq 0 ] ; then
echo "Another \"${MOUNT_POINT}\" already attached."
DEVICE=`/sbin/mount |/usr/bin/grep "${MOUNTED_POINT}"
2>/dev/null |/usr/bin/cut -d" " -f1`
if [ -b "${DEVICE}" ] ; then
/usr/bin/hdiutil detach "${DEVICE}"
echo "Detaching \"${DEVICE}\"..."
fi
fi
done
}
SAVEDIR="`pwd`"
trap 'cd "${SAVEDIR}"' EXIT
if [ $# -ne 2 ] ; then
echo "usage: $0 <image folder> <config filepath>"
exit 1
fi
IMGDIR=$1
CONFIG=$2
# Check OS Version, Minimum is 10.2.8
OSVERSION=`/usr/bin/sw_vers |/usr/bin/grep ProductVersion |/usr/bin/cut -d: -f2`
MAJORVER=`echo ${OSVERSION} | /usr/bin/cut -d . -f2`
MVTEMP=`echo ${OSVERSION} | /usr/bin/cut -d. -f3`
MINORVER=${MVTEMP:-0}
if [ ${MAJORVER} -lt 3 ] ; then
# if less then 10.3
if [ ${MAJORVER} -ne 2 ] ; then
echo "This version of MacOS (${OSVERSION}) is not
supported."
exit 1;
else
if [ ${MINORVER} -lt 8 ] ; then
echo "This version of MacOS (${OSVERSION}) is not
supported."
exit 1;
fi
fi
HDIUTIL_OPTIONS=
else
# additional hdiutil options for 10.3 or above system
HDIUTIL_OPTIONS="-private -noverify"
fi
# Check root volume is HFS
/sbin/mount -t hfs |/usr/bin/grep " / " 2>/dev/null
if [ $? -ne 0 ] ; then
echo "Root volume is not a HFS volume."
exit 5
fi
# validate the arguments
if [ ! -d "$IMGDIR" ] ; then
echo "$IMGDIR" does not exist.
exit 2
fi
if [ ! -r "$CONFIG" ] ; then
echo "$CONFIG" does not exist.
exit 3
fi
# Check running as root
MYUID=`/usr/bin/id -u`
if [ ${MYUID} -ne 0 ] ; then
echo "You need to be root to run the Adobe Creative Suite 2 Installer."
exit 4
fi
cd "${IMGDIR}"
IMGCOUNT=`/bin/ls -l *.dmg 2>/dev/null | /usr/bin/wc -l`
if [ -z "${IMGCOUNT}" -o "${IMGCOUNT}" = "0" ] ; then
echo "No disk image found in "${IMGDIR}"."
exit 2
fi
#detach any already attached installer images
detach_images
# Mount the disk images for the installer CDs
for DMG in *.dmg
do
# mount the remaining disk images
echo
echo "--- Attaching Installer disk image ${NUMBER}..."
echo /usr/bin/hdiutil attach -verbose -readonly ${HDIUTIL_OPTIONS}
"${DMG}"
/usr/bin/hdiutil attach -verbose -readonly ${HDIUTIL_OPTIONS} "${DMG}"
if [ $? -ne 0 ] ; then
echo "Error in attaching installer disk image: \"${DMG}\""
exit 6
fi
done
echo
echo
echo "---- Starting the Adobe Creative Suite Installer..."
echo
"/Volumes/Adobe Creative Suite Disk 1/Adobe Installer.app/Contents/MacOS/Adobe
Installer" --batch -c "${CONFIG}"
INSTALLATION_RESULT=$?
echo
#now detach attached installer images
detach_images
exit ${INSTALLATION_RESULT}