************************************************************************** Security Bulletin 9309 DISA Defense Communications System April 9, 1993 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, and concerns to security and 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-9302). ************************************************************************** + - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - + ! ! ! 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-93:06 CERT Advisory April 9, 1993 wuarchive ftpd Vulnerability --------------------------------------------------------------------------- The CERT Coordination Center has received information concerning a vulnerability in versions of wuarchive ftpd available before April 8, 1993. Vulnerable wuarchive ftpd versions were available from wuarchive.wustl.edu:/packages/ftpd.wuarchive.shar and many other anonymous FTP sites. We strongly recommend that any site using versions of wuarchive ftpd dating prior to April 8, 1993, immediately take corrective action or remove this service. --------------------------------------------------------------------------- I. Description A vulnerability exists in the access control mechanism in this version of ftpd. II. Impact Anyone (remote or local) can potentially gain access to any account including root on a host running this version of ftpd. III. Solution Affected sites may choose to disable anonymous FTP service until they have corrected this problem. Affected sites can correct this problem through one of the following two procedures: A. A new version of ftpd has been released that provides new features and also fixes this security problem. Sites can obtain this new version via anonymous FTP from wuarchive.wustl.edu (128.252.135.4). The files are located in: Size Checksum /packages/wuarchive-ftpd/wu-ftpd-2.0.shar 421953 08786 /packages/wuarchive-ftpd/wu-ftpd-2.0.tar 491520 27466 B. Make modifications to your existing wuarchive ftpd sources using the diff output provided below, recompile and install according to the instructions provided. *** ftpd.c.orig --- ftpd.c *************** *** 413,418 **** --- 413,420 ---- end_login(); } + anonymous = 0; + if (!strcasecmp(name, "ftp") || !strcasecmp(name, "anonymous")) { if (checkuser("ftp") || checkuser("anonymous")) { reply(530, "User %s access denied.", name); --------------------------------------------------------------------------- The CERT Coordination Center wishes to thank Scott Paisley, Computer Systems Support Manager, Factory Automated Systems Division, N.I.S.T., for informing us of this vulnerability. We would also like to thank Chris Myers, Washington University, for his quick response to this problem. --------------------------------------------------------------------------- If you believe that your system has been compromised, contact the CERT Coordination Center or your representative in FIRST (Forum of Incident Response and Security Teams). Internet E-mail: cert@cert.org Telephone: 412-268-7090 (24-hour hotline) CERT personnel answer 7:30 a.m.-6:00 p.m. EST(GMT-5)/EDT(GMT-4), on call for emergencies during other hours. CERT Coordination Center Software Engineering Institute Carnegie Mellon University Pittsburgh, PA 15213-3890 Past advisories, information about FIRST representatives, and other information related to computer security are available for anonymous FTP from cert.org (192.88.209.5). **************************************************************************** * * * The point of contact for MILNET security-related incidents is the * * Security Coordination Center (SCC). * * * * E-mail address: SCC@NIC.DDN.MIL * * * * Telephone: 1-(800)-365-3642 * * * * NIC Help Desk personnel are available from 7:00 a.m.-7:00 p.m. EST, * * Monday through Friday except on federal holidays. * * * ****************************************************************************