------------------------------------------------------------------------ bugfiler vulnerability September 1997 ------------------------------------------------------------------------ Systems Affected: Certain AIX machines. Others: unknown. (Vulnerability seen on AIX 3.* systems; no AIX 4.* machine inspected exhibited the flaw; all AIX 3.* machines inspected were vulnerable; very limited sample size though) Description: bugfiler (/lib/bugfiler) is SUID root. Impact: Local users can circumvent file access restrictions, leading to increased privileges. Depending on the installation of the system, root privileges may be gained. Exploit: $whoami eviluser $/lib/bugfiler -b creates funny files under the -owned and that may be used by crackers to increase privileges. See the manpage of bugfiler for more information. (bugfiler does not work for some s) Further information: bugfiler is intended to be run from a mail alias, handle bug reports piped to it, and maintain a database of bug reports in the specified directory. There should be no need for mere mortals executing it, and it should be prevented that local users run it. On systems not using bugfiler at all, the suggestion for the admin is to simply remove the SUID bit from all bugfiler binaries. (The actual fix may differ from system to system.) Mail from " (Bugs Bunny)" may mean that /lib/bugfiler was executed.