-----BEGIN PGP SIGNED MESSAGE----- __________________________________________________________ The U.S. Department of Energy Computer Incident Advisory Capability ___ __ __ _ ___ / | /_\ / \___ __|__ / \ \___ __________________________________________________________ INFORMATION BULLETIN Vulnerability in innd February 21, 1997 00:00 GMT Number H-34a _____________________________________________________________________________ PROBLEM: A vulnerability exists in all versions of INN (InterNetNews server) up to and including version 1.5. PLATFORM: Systems using any of the listed vendors may be vulnerable. Berkeley Software Design, Inc. (BSDI) Caldera Cray Research - A Silicon Graphics Company Debian Linux Red Hat DAMAGE: Remote users may run local commands on the server. SOLUTION: Upgrade to INN 1.5.1. Until you can do so, install available patches. _____________________________________________________________________________ VULNERABILITY Exploit details involving this vulnerability have been made ASSESSMENT: publicly available. _____________________________________________________________________________ [ Start CERT Advisory ] ============================================================================= CERT(sm) Advisory CA-97.08 Original issue date: February 20, 1997 Last revised: -- Topic: Vulnerability in innd - ----------------------------------------------------------------------------- The CERT Coordination Center has received reports that a vulnerability exists in all versions of INN (InterNetNews server) up to and including version 1.5. This vulnerability allows unauthorized users to execute arbitrary commands on the machine running INN by sending a maliciously formed news control message. Because the problem is with the content of news control messages, attacks can be launched remotely and may reach news servers located behind Internet firewalls. The CERT/CC recommends that sites upgrade to INN 1.5.1. Until you can do so, we urge you to apply the patch described in Sec. III.B. Information about this vulnerability has been widely distributed. We will update this advisory as we receive additional information. Please check advisory files regularly for updates that relate to your site. - ----------------------------------------------------------------------------- I. Description The INN daemon (innd) processes "newgroup" and "rmgroup" control Messages in a shell script (parsecontrol) that uses the shell's "eval" command. However, some of the information passed to eval comes from the message without adequate checks for characters that are special to the shell. This permits anyone who can send messages to an INN server - almost anyone with Usenet access - to execute arbitrary commands on that server. These commands run with the uid and privileges of the "innd" process on that server. Because such messages are usually passed through Internet firewalls to a site's news server, servers behind such firewalls are vulnerable to attack. Also, the program executes these commands before checking whether the sender is authorized to create or remove newsgroups, so checks at that level (such as running pgpverify) do not prevent this problem. All versions of INN through 1.5 are vulnerable. You can determine which version of INN your site is running by connecting to the NNTP port (119) of your news server. For example: % telnet news.your.site 119 Connected to news.your.site Escape character is '^]'. 200 news.your.site InterNetNews server INN 1.4unoff4 05-Mar-96 ready Type "quit" to exit the connection. Note that this does not indicate whether or not the patch recommended below has been installed. II. Impact Remote, unauthorized users can execute arbitrary commands on the system with the same privileges as the innd (INN daemon) process. III. Solution Upgrade to INN 1.5.1. Until you can do so, install the patches available from James Brister or get help from your vendor, if it is available. A. Upgrade to INN 1.5.1 The current version of INN is 1.5.1, which does not have this vulnerability. Archive sites for INN version 1.5.1 along with additional information about INN are given at http://www.isc.org/inn.html The MD5 checksum for the gzip'ed tar file is MD5 (inn-1.5.1.tar.gz) = 555d50c42ba08ece16c6cdfa392e0ca4 B. Install patches Until you are able to upgrade to INN 1.5.1, we recommend installing the following patches, which have been made available by James Brister, the current maintainer of INN. For releases inn1.4unoff3, inn1.4unoff4, and inn1.5 (all versions), apply "security-patch.01" at ftp://ftp.isc.org/isc/inn/patches/security-patch.01 MD5 (security-patch.01) = 06131a3d1f4cf19d7d1e664c10306fa8 For release 1.4sec, Brister recommends upgrading to a newer version, but he has made the patch "security-patch.02" available at ftp://ftp.isc.org/isc/inn/patches/security-patch.02 MD5 (security-patch.02) = 3a964ba0b2b2baf678ef554c67bb28f2 C. Consult your vendor Below is a list of vendors who have provided information about this problem. Details are in Appendix A of this advisory; we will update the appendix as we receive more information. If your vendor's name is not on this list, the CERT/CC did not hear from that vendor. Please contact your vendor directly. Berkeley Software Design, Inc. (BSDI) Caldera Cray Research - A Silicon Graphics Company Debian Linux Red Hat - ----------------------------------------------------------------------------- Appendix A - Vendor Information Below is a list of the vendors who have provided information for this advisory. We will update this appendix as we receive additional information. If you do not see your vendor's name, the CERT/CC did not hear from that vendor. Please contact the vendor directly. Berkeley Software Design, Inc. (BSDI) ==================================== We ship INN as part of our distribution. BSD/OS 2.1 includes INN 1.4sec and 2.1 users should apply the patch referenced in the advisory. BSD/OS 3.0 includes INN 1.4unoff4 and the patch for that version is already included so BSD/OS 3.0 is not vulnerable as distributed. Caldera ======= An upgrade package for Caldera OpenLinux Base 1.0 will appear at Caldera's site: ftp://ftp.caldera.com/pub/col-1.0/updates/Helsinki/004/inn-1.5.1-2.i386.rpm MD5 sum is: 3bcd3120b93f41577d3246f3e9276098 inn-1.5.1-2.i386.rpm Cray Research - A Silicon Graphics Company ========================================== Cray Research has never shipped any news server with Unicos. Debian Linux ============ The current version of INN shipped with Debian is 1.4unoff4. However the "unstable" (or development) tree contains inn-1.5.1. It can be gotten from any debian mirror in the subdirectory debian/unstable/binary/news d3603d9617fbf894a3743a330544b62e 591154 news optional inn_1.5.1-1_i386.deb 205850779d2820f03f2438d063e1dc51 45230 news optional inn-dev_1.5.1-1_i386.deb badbe8431479427a4a4de8ebd6e1e150 31682 news optional inewsinn_1.5.1-1_i386 .deb Red Hat ======= All users of Red Hat 4.0 and Red Hat 4.1 are urged to upgrade to the inn-1.5.1-3 package available from ftp.redhat.com. The same package will work on both 4.0 and 4.1 systems, and is available from ftp.redhat.com in /updates/4.0 and /updates/4.1. Users with direct Internet connections can upgrade with one of the following commands: i386: rpm -Uvh ftp://ftp.redhat.com/updates/4.1/i386/inn-1.5.1-3.i386.rpm alpha (note the --ignorearch is only needed for Red Hat 4.0/AXP users): rpm -Uvh --ignorearch \ ftp://ftp.redhat.com/4.1/updates/i386/inn-1.5.1-3.alpha.rpm SPARC: rpm -Uvh ftp://ftp.redhat.com/updates/4.1/sparc/inn-1.5.1-3.alpha.rpm All of these packages have been signed with Red Hat's PGP key, which is availble on all Red Hat CDROMs, ftp.redhat.com, and public keyservers. [ End CERT Advisory ] _____________________________________________________________________________ CIAC wishes to acknowledge the contributions of CERT, James Brister of the Internet Software Consortium, Matt Power of MIT, Erik Troan of Red Hat & AUSCERT for the information contained in this bulletin. _____________________________________________________________________________ CIAC, the Computer Incident Advisory Capability, is the computer security incident response team for the U.S. Department of Energy (DOE) and the emergency backup response team for the National Institutes of Health (NIH). CIAC is located at the Lawrence Livermore National Laboratory in Livermore, California. CIAC is also a founding member of FIRST, the Forum of Incident Response and Security Teams, a global organization established to foster cooperation and coordination among computer security teams worldwide. CIAC services are available to DOE, DOE contractors, and the NIH. CIAC can be contacted at: Voice: +1 510-422-8193 FAX: +1 510-423-8002 STU-III: +1 510-423-2604 E-mail: ciac@llnl.gov For emergencies and off-hour assistance, DOE, DOE contractor sites, and the NIH may contact CIAC 24-hours a day. During off hours (5PM - 8AM PST), call the CIAC voice number 510-422-8193 and leave a message, or call 800-759-7243 (800-SKY-PAGE) to send a Sky Page. CIAC has two Sky Page PIN numbers, the primary PIN number, 8550070, is for the CIAC duty person, and the secondary PIN number, 8550074 is for the CIAC Project Leader. Previous CIAC notices, anti-virus software, and other information are available from the CIAC Computer Security Archive. World Wide Web: http://ciac.llnl.gov/ Anonymous FTP: ciac.llnl.gov (128.115.19.53) Modem access: +1 (510) 423-4753 (28.8K baud) +1 (510) 423-3331 (28.8K baud) CIAC has several self-subscribing mailing lists for electronic publications: 1. 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A list of FIRST member organizations and their constituencies can be obtained via WWW at http://www.first.org/. This document was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor the University of California nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial products, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation or favoring by the United States Government or the University of California. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or the University of California, and shall not be used for advertising or product endorsement purposes. LAST 10 CIAC BULLETINS ISSUED (Previous bulletins available from CIAC) H-24: IBM AIX(r) "gethostbyname()" Buffer Overrun Vulnerability H-25: Vulnerability in rlogin/term H-26: FreeBSD setlocale() Vulnerability H-27: HP-UX vgdisplay Buffer Overrun Vulnerability H-28: SGI IRIX startmidi/stopmidi Vulnerability H-29: HP-UX sendmail Patches Vulnerability H-30: Solaris ffbconfig Buffer Overrun Vulnerability H-31: HP-UX ppl executable Vulnerability H-32: HP-UX ppl Core Dump Vulnerability H-33: HP-UX ftpd/kftpd Vulnerability RECENT CIAC NOTES ISSUED (Previous Notes available from CIAC) Notes 07 - 3/29/95 A comprehensive review of SATAN Notes 08 - 4/4/95 A Courtney update Notes 09 - 4/24/95 More on the "Good Times" virus urban legend Notes 10 - 6/16/95 PKZ300B Trojan, Logdaemon/FreeBSD, vulnerability in S/Key, EBOLA Virus Hoax, and Caibua Virus Notes 11 - 7/31/95 Virus Update, Hats Off to Administrators, America On-Line Virus Scare, SPI 3.2.2 Released, The Die_Hard Virus Notes 12 - 9/12/95 Securely configuring Public Telnet Services, X Windows, beta release of Merlin, Microsoft Word Macro Viruses, Allegations of Inappropriate Data Collection in Win95 Notes 96-01 - 3/18/96 Java and JavaScript Vulnerabilities, FIRST Conference Announcement, Security and Web Search Engines, Microsoft Word Macro Virus Update -----BEGIN PGP SIGNATURE----- Version: 2.6.2 iQCVAwUBMxIuuLnzJzdsy3QZAQHVKQQAkO6jaNJ6tY5hFhFo8DHhS5SFyLSLi+5p waJE7mSvrfJ8za4m41k3qvCHQrEuIoICeij7IxSc1jIup5BDPJw1kGq1vdojC9IL 07kcglgNQeiOlQH7xfwafKxI2G7QQMA/kVTF7+fARXBtar97DdYCjraJjFaJLKf0 Whk6hqbCArw= =kjsO -----END PGP SIGNATURE-----