-----BEGIN PGP SIGNED MESSAGE----- <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Automated Systems Security Incident Support Team _____ ___ ___ _____ ___ _____ | / /\ / \ / \ | / \ | | / Integritas / \ \___ \___ | \___ | | < et /____\ \ \ | \ | | \ Celeritas / \ \___/ \___/ __|__ \___/ | |_____\ <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Bulletin 95-51 Release date: 18 December, 1995, 3:10 PM EST (GMT -5) SUBJECT: Widespread Internet system attacks. SUMMARY: ASSIST has received information from the CERT Coordination Center about a large number of Internet attacks, including some successful root level compromises, which have been noted during the past several weeks. BACKGROUND: Hundreds of attacks against Internet sites have been detected, and it is presumed many more attacks are going un-detected. All vulnerabilitites exploited in this group of attacks have been documented and have specific countermeasures (see RECOMMENDED SOLUTIONS for references to appropriate ASSIST bulletins). Intruders are using one or more of the following vulnerabilities and/or procedures in their attacks: * automated tools scan sites for NFS and NIS vulnerabilities * exploiting the rpc.ypupdated vulnerability to gain root access * exploiting the loadmodule vulnerability to gain root access * installing Trojan horse programs and packet sniffers * launching IP spoofing attacks IMPACT: Successful exploitation of the vulnerabilities can result in unauthorized root access. RECOMMENDED SOLUTIONS: Check systems to ensure that all the vulnerabilities and security issues addressed in the ASSIST bulletins cited below have been corrected. Back issues of all ASSIST bulletins can be downloaded from the ASSIST BBS and FTP systems (see ASSIST Information Resources paragraph in the trailer of this message). A. Automated tools scan sites for NFS and NIS vulnerabilities. * ASSIST 94-41, NFS Vulnerabilities. NOTE: The following is an addendum to 94-41. Some sites may run NFS on a port other than 2049. To determine which port is running NFS, enter the following command on the machine in question: rpcinfo -p If NFS is on a different port, then that is the port number to block at the firewall. * ASSIST 92-39, SunOS NIS Vulnerability. B. Exploiting the rpc.ypupdated vulnerability to gain root access. * ASSIST 95-49, rpc.ypupdated Vulnerability. * ASSIST 95-50, SGI rpc.ypupdated Vulnerability. C. Exploiting the loadmodule vulnerability to gain root access. * ASSIST 93-33, SunOS/Solbourne loadmodule and modload Vulnerability. * ASSIST 95-40, Sun 4.1.X Loadmodule Vulnerability. D. Installing Trojan horse programs and packet sniffers. * ASSIST 94-02, Ongoing network monitoring attacks, also see follow up bulletins 94-02A/B/C. NOTE: The following is an addendum to the 94-02 series. Check for modifications to /etc/rc* files and /etc/shutdown. Some intruders have modified /etc/rc files to ensure that the sniffer restarts after a shutdown or reboot. Others have modified the shutdown sequence to remove all traces of compromise. Look for additional Trojan binaries, in particular: netstat, ifconfig, su, ls, find, du, df, libc, sync, and any binaries referred in /etc/inetd.conf. Look for unexpected ASCII files in the /dev directory. Some of the Trojan binaries rely on configuration files, which are often found in /dev. Some sites have reported intruders gaining root access then reinstalling a kernel with /dev/nit functionality. Sniffers for other platforms, i.e., Solaris. Sites have reported intruders using sniffers to capture authentication to routers. Using that data, they compromise the routers and modify the configuration file. E. Launching IP spoofing attacks. * ASSIST 95-01, IP Spoofing Attacks and Hijacked Terminal Connections. * ASSIST 95-29, IP Spoofing Attacks. * ASSIST 95-29.readme. <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> ASSIST would like to thank the CERT Coordination Center for information contained in this bulletin. <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> ASSIST is an element of the Defense Information Systems Agency (DISA), and provides service to the entire DoD community. Constituents of the DoD with questions about ASSIST or computer security issues, can contact ASSIST using one of the methods listed below. Non-DoD organizations/institutions, contact the Forum of Incident Response and Security Teams (FIRST) representative. To obtain a list of FIRST member organizations and their constituencies send an email to docserver@first.org with an empty "subject" line and a message body containing the line "send first-contacts". ASSIST Information Resources: To be included in the distribution list for the ASSIST bulletins, send your Milnet (Internet) e-mail address to assist-request@assist.mil. Back issues of ASSIST bulletins, and other security related information, are available from the ASSIST BBS at 703-607-4710, 327-4710, and through anonymous FTP from assist.mil (IP address 199.211.123.11). Note: assist.mil will only accept anonymous FTP connections from Milnet addresses that are registered with the NIC or DNS. If your system is not registered, you must provide your MILNET IP address to ASSIST before access can be provided. ASSIST Contact Information: PHONE: 800-357-4231, COMM 703-607-4700, DSN 327-4700. ELECTRONIC MAIL: assist@assist.mil. ASSIST BBS: COMM 703-607-4710, DSN 327-4710, leave a message for the "sysop". FAX: COMM 703-607-4735, DSN 607-4735 ASSIST uses Pretty Good Privacy (PGP) 2.6.2 as the digital signature mechanism for bulletins. PGP 2.6.2 incorporates the RSAREF(tm) Cryptographic Toolkit under license from RSA Data Security, Inc. A copy of that license is available via anonymous FTP from net-dist.mit.edu (IP 18.72.0.3) in the file /pub/PGP/rsalicen.txt, and through the world wide web from http://net-dist.mit.edu/pgp.html. In accordance with the terms of that license, PGP 2.6.2 may be used for non-commercial purposes only. Instructions for downloading the PGP 2.6.2 software can also be obtained from net-dist.mit.edu in the pub/PGP/README file. PGP 2.6.2 and RSAREF may be subject to the export control laws of the United States of America as implemented by the United States Department of State Office of Defense Trade Controls. The PGP signature information will be attached to the end of ASSIST bulletins. Reference herein to any specific commercial product, process, or service by trade name, trademark manufacturer, or otherwise, does not constitute or imply its endorsement, recommendation, or favoring by ASSIST. 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