______________________________________________________________________________ SuSE Security Announcement Package: lsh Announcement-ID: SuSE-SA:2003:041 Date: Wed Oct 1 10:24:45 CEST 2003 Affected products: 8.0, 8.1, 8.2 Vulnerability Type: remote code execution Severity (1-10): 5 SuSE default package: yes Cross References: - Content of this advisory: 1) security vulnerability resolved: Buffer overflow in lsh. problem description, discussion, solution and upgrade information 2) pending vulnerabilities, solutions, workarounds: - node - proftp - OpenSSL 3) standard appendix (further information) ______________________________________________________________________________ 1) problem description, brief discussion, solution, upgrade information LSH is the GNU implementation of SSH and can be seen as an alternative to OpenSSH. Recently various remotely exploitable buffer overflows have been reported in LSH. These allow attackers to execute arbitrary code as root on un-patched systems. LSH is not installed by default on SuSE Linux. An update is therefore only recommended if you run LSH. Maintained SuSE products are not affected by this bug as LSH is not packaged on maintained products such as the Enterprise Server. For the updates to take effect execute the following command as root: /usr/sbin/rclshd restart Please download the update package for your distribution and verify its integrity by the methods listed in section 3) of this announcement. Then, install the package using the command "rpm -Fhv file.rpm" to apply the update. Our maintenance customers are being notified individually. The packages are being offered to install from the maintenance web. i386 Intel Platform: SuSE-8.2: 798f52402cda6c7e1733aed15bf0d9cb patch rpm(s): 9308cdb133d2311a9dc4a10bbf613501 source rpm(s): 1e1b5beac002cf51d1eea0277934a69d SuSE-8.1: b5ff8ba104623fe9a77705154aad92f7 patch rpm(s): 6341acd3fe513921b7123d7c1d98cc43 source rpm(s): 0a2b95e911f8760009ad0d5b2fd7618e SuSE-8.0: bccfd85985bab8a324b25c1b2443bf2b patch rpm(s): 8a232720cb0a4b35d0899e9c6a4e80ae source rpm(s): 8e3e30b134b12400559152bb5c53d0f8 ______________________________________________________________________________ 2) Pending vulnerabilities in SuSE Distributions and Workarounds: - node A format string vulnerability has been fixed in the new node packages available on our ftp servers. An update is recommended if you use this package. - proftp A off-by-one buffer overflow has been fixed in the proftp packages for SuSE Linux 7.2 and 7.3. Note that the bug that was fixed is different from the 'ASCII File Transfer Buffer Overrun Vulnerability' (CAN-2003-0831). The proftp packages shipped by SuSE are not affected by CAN-2003-0831. - OpenSSL Critical bugs within the ASN.1 parsing routines have been reported recently. We are currently building new packages and will notify you in a separate advisory when the packages are available. ______________________________________________________________________________ 3) standard appendix: authenticity verification, additional information - Package authenticity verification: SuSE update packages are available on many mirror ftp servers all over the world. While this service is being considered valuable and important to the free and open source software community, many users wish to be sure about the origin of the package and its content before installing the package. There are two verification methods that can be used independently from each other to prove the authenticity of a downloaded file or rpm package: 1) md5sums as provided in the (cryptographically signed) announcement. 2) using the internal gpg signatures of the rpm package. 1) execute the command md5sumafter you downloaded the file from a SuSE ftp server or its mirrors. Then, compare the resulting md5sum with the one that is listed in the announcement. Since the announcement containing the checksums is cryptographically signed (usually using the key security@suse.de), the checksums show proof of the authenticity of the package. We disrecommend to subscribe to security lists which cause the email message containing the announcement to be modified so that the signature does not match after transport through the mailing list software. Downsides: You must be able to verify the authenticity of the announcement in the first place. If RPM packages are being rebuilt and a new version of a package is published on the ftp server, all md5 sums for the files are useless. 2) rpm package signatures provide an easy way to verify the authenticity of an rpm package. Use the command rpm -v --checksig to verify the signature of the package, where is the filename of the rpm package that you have downloaded. Of course, package authenticity verification can only target an un-installed rpm package file. Prerequisites: a) gpg is installed b) The package is signed using a certain key. The public part of this key must be installed by the gpg program in the directory ~/.gnupg/ under the user's home directory who performs the signature verification (usually root). You can import the key that is used by SuSE in rpm packages for SuSE Linux by saving this announcement to a file ("announcement.txt") and running the command (do "su -" to be root): gpg --batch; gpg < announcement.txt | gpg --import SuSE Linux distributions version 7.1 and thereafter install the key "build@suse.de" upon installation or upgrade, provided that the package gpg is installed. The file containing the public key is placed at the top-level directory of the first CD (pubring.gpg) and at . - SuSE runs two security mailing lists to which any interested party may subscribe: suse-security@suse.com - general/linux/SuSE security discussion. All SuSE security announcements are sent to this list. To subscribe, send an email to <suse-security-subscribe@suse.com>. suse-security-announce@suse.com - SuSE's announce-only mailing list. Only SuSE's security announcements are sent to this list. To subscribe, send an email to <suse-security-announce-subscribe@suse.com>. For general information or the frequently asked questions (faq) send mail to: <suse-security-info@suse.com> or <suse-security-faq@suse.com> respectively. ==================================================================== SuSE's security contact is <security@suse.com> or <security@suse.de>. The <security@suse.de> public key is listed below. ====================================================================______________________________________________________________________________ The information in this advisory may be distributed or reproduced, provided that the advisory is not modified in any way. In particular, it is desired that the clear-text signature shows proof of the authenticity of the text. SuSE Linux AG makes no warranties of any kind whatsoever with respect to the information contained in this security advisory. Type Bits/KeyID Date User ID pub 2048R/3D25D3D9 1999-03-06 SuSE Security Team <security@suse.de> pub 1024D/9C800ACA 2000-10-19 SuSE Package Signing Key <build@suse.de>