CERT Advisory October 26, 1989 Sun RCP vulnerability A problem has been discovered in the SunOS 4.0.x rcp. If exploited, this problem can allow users of other trusted machines to execute root-privilege commands on a Sun via rcp. This affects only SunOS 4.0.x systems; 3.5 systems are not affected. A Sun running 4.0.x rcp can be exploited by any other trusted host listed in /etc/hosts.equiv or /.rhosts. Note that the other machine exploiting this hole does not have to be running Unix; this vulnerability can be exploited by a PC running PC/NFS, for example. This bug will be fixed by Sun in version 4.1 (Sun Bug number 1017314), but for now the following workaround is suggested by Sun: Change the 'nobody' /etc/passwd file entry from nobody:*:-2:-2::/: to nobody:*:32767:32767:Mismatched NFS ID's:/nonexistant:/nosuchshell If you need further information about this problem, please contact CERT by electronic mail or phone. J. Paul Holbrook Computer Emergency Response Team (CERT) Carnegie Mellon University Software Engineering Institute Internet: (412) 268-7090 (24 hour hotline)