************************************************************************** Security Bulletin 9201 DISA Defense Communications System January 22,1992 Published by: DDN Security Coordination Center (SCC@NIC.DDN.MIL) 1-(800) 365-3642 DEFENSE DATA NETWORK SECURITY BULLETIN The DDN SECURITY BULLETIN is distributed by the DDN SCC (Security Coordination Center) under DISA contract as a means of communicating information on network and host security exposures, fixes, & concerns to security & management personnel at DDN facilities. Back issues may be obtained via FTP (or Kermit) from NIC.DDN.MIL [192.112.36.5] using login="anonymous" and password="guest". The bulletin pathname is SCC:DDN-SECURITY-yynn (where "yy" is the year the bulletin is issued and "nn" is a bulletin number, e.g. SCC:DDN-SECURITY-9201). ************************************************************************** + - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - + ! ! ! The following important advisory was issued by the Computer ! ! Emergency Response Team (CERT) and is being relayed unedited ! ! via the Defense Information Systems Agency's Security ! ! Coordination Center distribution system as a means of ! ! providing DDN subscribers with useful security information. ! ! ! + - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - + =========================================================================== CA-92:01 CERT Advisory January 20, 1992 NeXTstep Configuration Vulnerability --------------------------------------------------------------------------- The Computer Emergency Response Team/Coordination Center (CERT/CC) has received information concerning a vulnerability in release 2 of NeXTstep's NetInfo default configuration. This vulnerability will be corrected in future versions of NeXTstep. --------------------------------------------------------------------------- I. Description By default, a NetInfo server process will provide information to any machine that requests it. II. Impact Remote users can gain unauthorized access to the network's administrative information such as the passwd file. III. Solution Ensure that the trusted_networks property of each NetInfo domain's root NetInfo directory is set correctly, so that only those systems which should be obtaining information from NetInfo are granted access. The value for the trusted_networks property should be the network numbers of the networks the server should trust. Note that improperly setting trusted_networks can render your network unusable. Consult Chapter 16, "Security", of the "NeXT Network and System Administration" manual for release 2 for details on setting the trusted_networks property of the root NetInfo directory. --------------------------------------------------------------------------- The CERT/CC wishes to thank NeXT Computer, Inc. for their cooperation in documenting and publicizing this security vulnerability. --------------------------------------------------------------------------- If you believe that your system has been compromised, contact CERT/CC via telephone or e-mail. Internet E-mail: cert@cert.sei.cmu.edu Telephone: 412-268-7090 (24-hour hotline) CERT/CC personnel answer 7:30a.m.-6:00p.m. EST(GMT-5)/EDT(GMT-4), on call for emergencies during other hours. Computer Emergency Response Team/Coordination Center (CERT/CC) Software Engineering Institute Carnegie Mellon University Pittsburgh, PA 15213-3890 Past advisories and other information related to computer security are available for anonymous ftp from the cert.sei.cmu.edu (192.88.209.5) system.