-----BEGIN PGP SIGNED MESSAGE----- Caldera Security Advisory SA-1997.31: Additional Vulnerabilities in wu-ftpd Original report date: 11-Dec-1997 RPM build date: 12-Dec-1997 Advisory issue date: 16-Dec-1997 Topic: Additional Vulnerabilities in wu-ftpd 2.4.2 beta 15 I. Problem Description This document summarizes additional vulnerabilities in the wu-ftpd 2.4.2 beta 15 FTP server not covered by CERT Advisory CA-97.27 - "FTP_bounce". The list of affected platforms may not be limited to systems running under Linux. II. Impact Under certain circumstances wu-ftpd 2.4.2 beta 15 allows a remote user to open a connection to any service on a server running the vulnerable version of wu-ftpd. Under Linux, the connection will be established via the loopback interface which could bypass access controls that assume that connections can be established only via Ethernet, PPP or SLIP interfaces. Other types of exploits are possible. This problem was present on the following OpenLinux releases: Base 1.0 Lite 1.1 Base 1.1 Standard 1.1 To determine if you are affected and need this update execute the following: rpm -q wu-ftpd If the results show wu-ftpd-2.4.2b15-4 or earlier then you will need to update. NOTE: The problem described in CERT Advisory CA-97.27 suggests using wu-ftpd 2.4.2 beta 15. Versions of OpenLinux prior to 1.2 included wu-ftpd release 2.4.2 beta 13 or earlier. However, this should not be a problem if Caldera Security Advisory SA-1997.27 has already been applied since it recommends that wu-ftpd-2.4.2b15-4 be installed. But the version of wu-ftpd 2.4.2 beta 15 described in this document (wu-ftpd-2.4.2b15-5) contains *additional* security fixes. III. Solution The proper solution is to install the new wu-ftpd package. This package is located on Caldera's FTP server (ftp.caldera.com): The binary RPM can be obtained at: ftp://ftp.caldera.com/pub/openlinux/updates/1.1/current/RPMS The source RPM can be obtained at: ftp://ftp.caldera.com/pub/openlinux/updates/1.1/current/SRPMS All that is required to do to install the fix is the following: rpm -U wu-ftpd-2.4.2b15-5.i386.rpm The MD5 checksums (from the "md5sum" command) for these packages are: 1ce8038acc06eb200e87f2c8024df633 wu-ftpd-2.4.2b15-5.i386.rpm e81777eae4b6631fd3a9a238bd5da0be wu-ftpd-2.4.2b15-5.src.rpm IV. References / Credits This vulnerability was discovered and fixed by Olaf Kirch (email: okir@caldera.de). Other Linux vendors and CERT have been apprised of this vulnerability. Time is being given to other vendors to release their fixes before more details will be published. According to its maintainer, Stan Barber, release wu-ftpd 2.4.2 Beta 16 is expected on or before 25-Dec-1997. The CERT Coordination Center is located at: http://www.cert.org CERT Advisory CA-97.27: "FTP Bounce" (10-Dec-1997): http://www.cert.org/pub/advisories/1997/CA-97.27.FTP_bounce.html CERT Tech Tip "Problems With The FTP PORT Command" (10-Dec-1997): ftp://ftp.cert.org/pub/tech_tips/FTP_PORT_attacks White Paper: "The FTP Bounce Attack" (12-Jul-1995): ftp://avian.org/random/ftp-attack Caldera Security Advisory SA-1997.27: "Vulnerability in wu-ftpd": http://www.caldera.com/tech-ref/security/SA-1997.27.html This advisory and other Caldera security resources are located at: http://www.caldera.com/tech-ref/security/ This Security Alert closes Caldera internal problem report #1361. V. PGP Signature This message was signed with the PGP key for security@caldera.com. This key can be obtained from: ftp://ftp.caldera.com/pub/pgp-keys/ Or on an OpenLinux CDROM under: /OpenLinux/pgp-keys/ $Id: SA-1997.31,v 1.2 1997/12/16 06:09:27 ron Exp $ -----BEGIN PGP SIGNATURE----- Version: 2.6.2 iQCVAwUBNJYbPOn+9R4958LpAQFYPAP/f3X6Apddh0akqgKK2C93PQlm44R2Ti1B WDZ9wHCspT/PboQadsT7MYidjJUOn3HdxQRgVWr2IMFy12N8v6azrYQU+4BxI4p/ f5wEpE0dlueRpyXZ4wyOMh6YhKubgXIRfwPeTIZnjpIjkYpTQUlIgWCFY7ISC1Te 6doYxvrTggg= =KW2w -----END PGP SIGNATURE-----