=========================================================================== 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).