login in Slackware Linux 3.2 through 3.5 does not properly check for an error when the /etc/group file is missing, which prevents it from dropping privileges, causing it to assign root privileges to any local user who logs on to the server.
Buffer overflow in TestChip function in XFree86 SuperProbe in Slackware Linux 3.1 allows local users to gain root privileges via a long -nopr argument.
rcp on various Linux systems including Red Hat 4.0 allows a "nobody" user or other user with UID of 65535 to overwrite arbitrary files, since 65535 is interpreted as -1 by chown and other system calls, which causes the calls to fail to modify the ownership of the file.