>> It appears that the completely undocumented routine 'nfs_mount' can >> be used by a non-root user to mount a daemon on a directory ala NFS. >> It seems to me that this is a very nasty security hole. > Here's a little additional information..... the nfs_mount routine > does its work through the vmount() system call, which is documented. > If this is a security hole at all, then it's because it would let an > attacker mount a remote filesystem under his control onto a > world-readable directory like /tmp or /var/preserve, and thereby grab > a copy of everything that was written to that directory. I don't have access to AIX, so I can't read the vmount() docs, so this may be a non-issue...but unless it enforces "nosuid,nodev" for non-root mounts, there are much greater problems - like someone mounting a filesystem providing suid executables, or device special files with permissive mode bits. (Note that if, as the first message implies, vmount() allows the mounting of a daemon on a directory, then these executables and/or special files do not have to actually exist anywhere; root access on another machine is not needed.) der Mouse mouse@collatz.mcrcim.mcgill.edu