__________________________________________________________ The U.S. Department of Energy Computer Incident Advisory Center ___ __ __ _ ___ / | /_\ / \___ __|__ / \ \___ __________________________________________________________ INFORMATION BULLETIN Red Hat OpenSSH Vulnerability [Red Hat Advisory RHSA-2001:114-05] October 24, 2001 00:00 GMT Number M-010 ______________________________________________________________________________ PROBLEM: If a user lists multiple keys in their ".ssh/authorized_keys2" file, sshd may in some circumstances not honor the "from" option which can be associated with a key, thus allowing unauthorized users to log in from hosts that have been denied access. PLATFORM: Red Hat Linux 7.0 - alpha, i386 Red Hat Linux 7.1 - alpha, i386, ia64 Red Hat Linux 7.2 - i386 DAMAGE: The vulnerability may allow unauthorized users to log in from hosts that have been denied access. SOLUTION: Before applying this update, make sure all previously released errata relevant to your system have been applied. Proceed to install updated openssh packages as prescribed below. ______________________________________________________________________________ VULNERABILITY The risk is LOW. An attacker must have access to an authorized ASSESSMENT: account (username and password) on the machine being attacked. ______________________________________________________________________________ LINKS: CIAC BULLETIN: http://www.ciac.org/ciac/bulletins/m-010.shtml ______________________________________________________________________________ [***** Start Red Hat Advisory RHSA-2001:114-05 *****] --------------------------------------------------------------------- Red Hat, Inc. Red Hat Security Advisory Synopsis: Updated openssh packages available Advisory ID: RHSA-2001:114-05 Issue date: 2001-09-27 Updated on: 2001-10-19 Product: Red Hat Linux Keywords: openssh source IP Cross references: Obsoletes: --------------------------------------------------------------------- 1. Topic: Updated openssh packages are now available for Red Hat Linux 7 and 7.1. These packages fix a vulnerability which may allow unauthorized users to log in from hosts that have been denied access. 2001-10-22: Pacakges are now available for Red Hat Linux 7.2. 2. Relevant releases/architectures: Red Hat Linux 7.0 - alpha, i386 Red Hat Linux 7.1 - alpha, i386, ia64 Red Hat Linux 7.2 - i386 3. Problem description: If a user lists multiple keys in her .ssh/authorized_keys2 file, sshd may in some circumstances not honor the "from" option which can be associated with a key, thereby allowing key-based logins from hosts which should not be allowed access. 4. Solution: Before applying this update, make sure all previously released errata relevant to your system have been applied. To update all RPMs for your particular architecture, run: rpm -Fvh [filenames] where [filenames] is a list of the RPMs you wish to upgrade. Only those RPMs which are currently installed will be updated. Those RPMs which are not installed but included in the list will not be updated. Note that you can also use wildcards (*.rpm) if your current directory *only* contains the desired RPMs. Please note that this update is also available via Red Hat Network. Many people find this an easier way to apply updates. To use Red Hat Network, launch the Red Hat Update Agent with the following command: up2date This will start an interactive process that will result in the appropriate RPMs being upgraded on your system. 5. Bug IDs fixed (http://bugzilla.redhat.com/bugzilla for more info): 6. RPMs required: Red Hat Linux 7.0: SRPMS: ftp://updates.redhat.com/7.0/en/os/SRPMS/openssh-2.9p2-8.7.src.rpm alpha: ftp://updates.redhat.com/7.0/en/os/alpha/openssh-2.9p2-8.7.alpha.rpm ftp://updates.redhat.com/7.0/en/os/alpha/openssh-clients-2.9p2-8.7.alpha.rpm ftp://updates.redhat.com/7.0/en/os/alpha/openssh-server-2.9p2-8.7.alpha.rpm ftp://updates.redhat.com/7.0/en/os/alpha/openssh-askpass-2.9p2-8.7.alpha.rpm ftp://updates.redhat.com/7.0/en/os/alpha/openssh-askpass-gnome-2.9p2-8.7.alpha.rpm i386: ftp://updates.redhat.com/7.0/en/os/i386/openssh-2.9p2-8.7.i386.rpm ftp://updates.redhat.com/7.0/en/os/i386/openssh-clients-2.9p2-8.7.i386.rpm ftp://updates.redhat.com/7.0/en/os/i386/openssh-server-2.9p2-8.7.i386.rpm ftp://updates.redhat.com/7.0/en/os/i386/openssh-askpass-2.9p2-8.7.i386.rpm ftp://updates.redhat.com/7.0/en/os/i386/openssh-askpass-gnome-2.9p2-8.7.i386.rpm Red Hat Linux 7.1: SRPMS: ftp://updates.redhat.com/7.1/en/os/SRPMS/openssh-2.9p2-8.7.src.rpm alpha: ftp://updates.redhat.com/7.1/en/os/alpha/openssh-2.9p2-8.7.alpha.rpm ftp://updates.redhat.com/7.1/en/os/alpha/openssh-clients-2.9p2-8.7.alpha.rpm ftp://updates.redhat.com/7.1/en/os/alpha/openssh-server-2.9p2-8.7.alpha.rpm ftp://updates.redhat.com/7.1/en/os/alpha/openssh-askpass-2.9p2-8.7.alpha.rpm ftp://updates.redhat.com/7.1/en/os/alpha/openssh-askpass-gnome-2.9p2-8.7.alpha.rpm i386: ftp://updates.redhat.com/7.1/en/os/i386/openssh-2.9p2-8.7.i386.rpm ftp://updates.redhat.com/7.1/en/os/i386/openssh-clients-2.9p2-8.7.i386.rpm ftp://updates.redhat.com/7.1/en/os/i386/openssh-server-2.9p2-8.7.i386.rpm ftp://updates.redhat.com/7.1/en/os/i386/openssh-askpass-2.9p2-8.7.i386.rpm ftp://updates.redhat.com/7.1/en/os/i386/openssh-askpass-gnome-2.9p2-8.7.i386.rpm ia64: ftp://updates.redhat.com/7.1/en/os/ia64/openssh-2.9p2-8.7.ia64.rpm ftp://updates.redhat.com/7.1/en/os/ia64/openssh-clients-2.9p2-8.7.ia64.rpm ftp://updates.redhat.com/7.1/en/os/ia64/openssh-server-2.9p2-8.7.ia64.rpm ftp://updates.redhat.com/7.1/en/os/ia64/openssh-askpass-2.9p2-8.7.ia64.rpm ftp://updates.redhat.com/7.1/en/os/ia64/openssh-askpass-gnome-2.9p2-8.7.ia64.rpm Red Hat Linux 7.2: SRPMS: ftp://updates.redhat.com/7.2/en/os/SRPMS/openssh-2.9p2-9.src.rpm i386: ftp://updates.redhat.com/7.2/en/os/i386/openssh-2.9p2-9.i386.rpm ftp://updates.redhat.com/7.2/en/os/i386/openssh-clients-2.9p2-9.i386.rpm ftp://updates.redhat.com/7.2/en/os/i386/openssh-server-2.9p2-9.i386.rpm ftp://updates.redhat.com/7.2/en/os/i386/openssh-askpass-2.9p2-9.i386.rpm ftp://updates.redhat.com/7.2/en/os/i386/openssh-askpass-gnome-2.9p2-9.i386.rpm 7. Verification: MD5 sum Package Name -------------------------------------------------------------------------- 2cb978dd97527b75dd765cc7866747be 7.0/en/os/SRPMS/openssh-2.9p2-8.7.src.rpm 3f25b21ea52cf287b3f92dde9ebeb6e5 7.0/en/os/alpha/openssh-2.9p2-8.7.alpha.rpm 0aa7e84cf7051625c266fd06097f5421 7.0/en/os/alpha/openssh-askpass-2.9p2-8.7.alpha.rpm b0bc920fb83c38f91696283ae9a35c70 7.0/en/os/alpha/openssh-askpass-gnome-2.9p2-8.7.alpha.rpm 3ba198d73c0c2b98b1d28b1209529704 7.0/en/os/alpha/openssh-clients-2.9p2-8.7.alpha.rpm b6190a028673032994ccc21cf2a1d620 7.0/en/os/alpha/openssh-server-2.9p2-8.7.alpha.rpm 968125b43cb68330aa58a85e082573c6 7.0/en/os/i386/openssh-2.9p2-8.7.i386.rpm 913350e14f7e40c1cbaaf01a68ff2af6 7.0/en/os/i386/openssh-askpass-2.9p2-8.7.i386.rpm 62aac745851160f5805eaee52cdb6eb9 7.0/en/os/i386/openssh-askpass-gnome-2.9p2-8.7.i386.rpm d2831ff8f3032462b511ec9bd8e486f2 7.0/en/os/i386/openssh-clients-2.9p2-8.7.i386.rpm 3a995bf67827eaa272976df85939d778 7.0/en/os/i386/openssh-server-2.9p2-8.7.i386.rpm 2cb978dd97527b75dd765cc7866747be 7.1/en/os/SRPMS/openssh-2.9p2-8.7.src.rpm 917606bec87a2598db083075248d63f3 7.1/en/os/alpha/openssh-2.9p2-8.7.alpha.rpm 59e697845982082983be668c1491f478 7.1/en/os/alpha/openssh-askpass-2.9p2-8.7.alpha.rpm b1a4c72deb5086d80b0065cd1ddf6ce4 7.1/en/os/alpha/openssh-askpass-gnome-2.9p2-8.7.alpha.rpm 16523f9c4e76c077dc10505fa1c46f2f 7.1/en/os/alpha/openssh-clients-2.9p2-8.7.alpha.rpm 4844484c7174ee970617579a4355639d 7.1/en/os/alpha/openssh-server-2.9p2-8.7.alpha.rpm 968125b43cb68330aa58a85e082573c6 7.1/en/os/i386/openssh-2.9p2-8.7.i386.rpm 913350e14f7e40c1cbaaf01a68ff2af6 7.1/en/os/i386/openssh-askpass-2.9p2-8.7.i386.rpm 62aac745851160f5805eaee52cdb6eb9 7.1/en/os/i386/openssh-askpass-gnome-2.9p2-8.7.i386.rpm d2831ff8f3032462b511ec9bd8e486f2 7.1/en/os/i386/openssh-clients-2.9p2-8.7.i386.rpm 3a995bf67827eaa272976df85939d778 7.1/en/os/i386/openssh-server-2.9p2-8.7.i386.rpm d2cfbc8f711499f14e850e3a39216b72 7.1/en/os/ia64/openssh-2.9p2-8.7.ia64.rpm 676181a27221581a0144d5987d42e5d8 7.1/en/os/ia64/openssh-askpass-2.9p2-8.7.ia64.rpm 48455412e34bd704d6c7516f5ed8208c 7.1/en/os/ia64/openssh-askpass-gnome-2.9p2-8.7.ia64.rpm 225d83ddfebb3eba7fe290c33c5c41cf 7.1/en/os/ia64/openssh-clients-2.9p2-8.7.ia64.rpm b6cfceece2ac8f5060ab63d6f7254770 7.1/en/os/ia64/openssh-server-2.9p2-8.7.ia64.rpm b8962a6f832e333d8fcf8782228f78e3 7.2/en/os/SRPMS/openssh-2.9p2-9.src.rpm c553416074a5fc54d309c6e7653f684a 7.2/en/os/i386/openssh-2.9p2-9.i386.rpm 557a7615d1abf68e4b2bb998c0091638 7.2/en/os/i386/openssh-askpass-2.9p2-9.i386.rpm 4b1df978407683e2c160f496f24e26e5 7.2/en/os/i386/openssh-askpass-gnome-2.9p2-9.i386.rpm f35d0f0b45fd5fd3ceb06589ca18aab3 7.2/en/os/i386/openssh-clients-2.9p2-9.i386.rpm d9fcc0d6d03c59b04681d6e755e3cb92 7.2/en/os/i386/openssh-server-2.9p2-9.i386.rpm These packages are GPG signed by Red Hat, Inc. for security. Our key is available at: http://www.redhat.com/about/contact/pgpkey.html You can verify each package with the following command: rpm --checksig If you only wish to verify that each package has not been corrupted or tampered with, examine only the md5sum with the following command: rpm --checksig --nogpg 8. References: http://www.securityfocus.com/cgi-bin/archive.pl?id=1&mid=216702&start=2001-09-24&end=2001-09-30 Copyright(c) 2000, 2001 Red Hat, Inc. [***** End Red Hat Advisory RHSA-2001:114-05 *****] _______________________________________________________________________________ CIAC wishes to acknowledge the contributions of Red Hat Linux for the information contained in this bulletin. _______________________________________________________________________________ CIAC, the Computer Incident Advisory Center, 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: +1 925-422-8193 (7x24) FAX: +1 925-423-8002 STU-III: +1 925-423-2604 E-mail: ciac@ciac.org Previous CIAC notices, anti-virus software, and other information are available from the CIAC Computer Security Archive. World Wide Web: http://www.ciac.org/ Anonymous FTP: ftp.ciac.org PLEASE NOTE: Many users outside of the DOE, ESnet, and NIH computing communities receive CIAC bulletins. If you are not part of these communities, please contact your agency's response team to report incidents. Your agency's team will coordinate with CIAC. The Forum of Incident Response and Security Teams (FIRST) is a world-wide organization. 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. 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