From agent99@sgi.com Sat Mar 30 00:59:30 2002 From: SGI Security Coordinator To: agent99@sgi.com Date: Thu, 28 Mar 2002 10:46:19 -0800 (PST) Subject: IRIX FTP Bounce vulnerability -----BEGIN PGP SIGNED MESSAGE----- ______________________________________________________________________________ SGI Security Advisory Title: IRIX FTP Bounce vulnerability Number: 20020305-01-I Date: March 28, 2002 Reference: CERT CA-1997-27 ______________________________________________________________________________ SGI provides this information freely to the SGI user community for its consideration, interpretation, implementation and use. SGI recommends that this information be acted upon as soon as possible. SGI provides the information in this Security Advisory on an "AS-IS" basis only, and disclaims all warranties with respect thereto, express, implied or otherwise, including, without limitation, any warranty of merchantability or fitness for a particular purpose. In no event shall SGI be liable for any loss of profits, loss of business, loss of data or for any indirect, special, exemplary, incidental or consequential damages of any kind arising from your use of, failure to use or improper use of any of the instructions or information in this Security Advisory. ______________________________________________________________________________ - ----------------------- - --- Issue Specifics --- - ----------------------- The IRIX ftpd server daemon can be used as a relay to portscan networks. The PORT command, part of the FTP protocol, can be used to establish connections to remote machines other than the FTP client. While this is functionality that complies with the FTP RFC, it leads to exposure to security risks. This is known as the "FTP bounce" vulnerability. SGI has investigated this issues and recommends the following steps for neutralizing the exposure. It is HIGHLY RECOMMENDED that these measures be implemented on ALL vulnerable SGI systems. - -------------- - --- Impact --- - -------------- An attacker may be able to scan networks that they wouldn't otherwise have access to. An attacker may be able to conceal the true origin of a portscanning attempt. CERT reported this vulnerability: http://www.cert.org/advisories/CA-1997-27.html This vulnerability has been publicly discussed in Usenet newsgroups and security mailing lists. - ---------------- - --- Solution --- - ---------------- With IRIX 6.5.6 or better, one can run the ftpd daemon with the -p option to prevent this vulnerability: 1) Become the root user on the system. % /bin/su - Password: # 2) Edit the file /etc/inetd.conf with your favorite text editor. # vi /etc/inetd.conf {Find the following line} ftp stream tcp nowait root /usr/etc/ftpd ftpd -l {Add the -p option} ftp stream tcp nowait root /usr/etc/ftpd ftpd -lp {Save the file} 3) Force inetd to re-read the configuration file. # /etc/killall -HUP inetd 4) Kill any existing ftpd process. # /etc/killall telnetd 5) Return to previous level. # exit % - ------------- - --- Links --- - ------------- SGI Security Advisories can be found at: http://www.sgi.com/support/security/ and ftp://patches.sgi.com/support/free/security/advisories/ SGI Security Patches can be found at: http://www.sgi.com/support/security/ and ftp://patches.sgi.com/support/free/security/patches/ SGI patches for IRIX can be found at the following patch servers: http://support.sgi.com/irix/ and ftp://patches.sgi.com/ SGI freeware updates for IRIX can be found at: http://freeware.sgi.com/ SGI fixes for SGI open sourced code can be found on: http://oss.sgi.com/projects/ SGI patches and RPMs for Linux can be found at: http://support.sgi.com/linux/ or http://oss.sgi.com/projects/sgilinux-combined/download/security-fixes/ SGI patches for Windows NT or 2000 can be found at: http://support.sgi.com/nt/ IRIX 5.2-6.4 Recommended/Required Patch Sets can be found at: http://support.sgi.com/irix/ and ftp://patches.sgi.com/support/patchset/ IRIX 6.5 Maintenance Release Streams can be found at: http://support.sgi.com/colls/patches/tools/relstream/index.html IRIX 6.5 Software Update CDs can be obtained from: http://support.sgi.com/irix/swupdates/ The primary SGI anonymous FTP site for security advisories and patches is patches.sgi.com (216.32.174.211). Security advisories and patches are located under the URL ftp://patches.sgi.com/support/free/security/ For security and patch management reasons, ftp.sgi.com (mirrors patches.sgi.com security FTP repository) lags behind and does not do a real-time update. - ------------------------ - --- Acknowledgments ---- - ------------------------ SGI wishes to thank CERT, NASA, and the users of the Internet Community at large for their assistance in this matter. - ----------------------------------------- - --- SGI Security Information/Contacts --- - ----------------------------------------- If there are questions about this document, email can be sent to security-info@sgi.com. ------oOo------ SGI provides security information and patches for use by the entire SGI community. This information is freely available to any person needing the information and is available via anonymous FTP and the Web. The primary SGI anonymous FTP site for security advisories and patches is patches.sgi.com (216.32.174.211). Security advisories and patches are located under the URL ftp://patches.sgi.com/support/free/security/ The SGI Security Headquarters Web page is accessible at the URL: http://www.sgi.com/support/security/ For issues with the patches on the FTP sites, email can be sent to security-info@sgi.com. For assistance obtaining or working with security patches, please contact your SGI support provider. ------oOo------ SGI provides a free security mailing list service called wiretap and encourages interested parties to self-subscribe to receive (via email) all SGI Security Advisories when they are released. Subscribing to the mailing list can be done via the Web (http://www.sgi.com/support/security/wiretap.html) or by sending email to SGI as outlined below. % mail wiretap-request@sgi.com subscribe wiretap end ^d In the example above, is the email address that you wish the mailing list information sent to. The word end must be on a separate line to indicate the end of the body of the message. The control-d (^d) is used to indicate to the mail program that you are finished composing the mail message. ------oOo------ SGI provides a comprehensive customer World Wide Web site. This site is located at http://www.sgi.com/support/security/ . ------oOo------ If there are general security questions on SGI systems, email can be sent to security-info@sgi.com. For reporting *NEW* SGI security issues, email can be sent to security-alert@sgi.com or contact your SGI support provider. A support contract is not required for submitting a security report. ______________________________________________________________________________ This information is provided freely to all interested parties and may be redistributed provided that it is not altered in any way, SGI is appropriately credited and the document retains and includes its valid PGP signature. -----BEGIN PGP SIGNATURE----- Version: 2.6.2 iQCVAwUBPKNPw7Q4cFApAP75AQFhdgQAplDzLYCd/UmLp0dkuDxRehpa0R3h1HLB BtY6QQWKo2vxOfR+JsSjKnz1k3S8uqfuPpGwZtJ6so9GqdRJEbys4qTk00FjJ9ak Lc9Xm2GSLckVeTnE46HVPYfrptVrOA67bBPhOIQhhXHkdxmKixD341O+n8Jgvfir 0g895ou4H6U= =DN26 -----END PGP SIGNATURE-----