Apple Remote Desktop root vulneravility

[fribitch () organic com]

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}