______________________________________________________________________________ SuSE Security Announcement Package: kdenetwork Announcement-ID: SuSE-SA:2002:042 Date: Tue Nov 12 10:00:00 CET 2002 Affected products: 7.2, 7.3 SuSE eMail Server III, 3.1 SuSE Firewall on CD SuSE Linux Connectivity Server SuSE Linux Enterprise Server 7 SuSE Linux Office Server Vulnerability Type: remote command execution Severity (1-10): 6 SuSE default package: yes Cross References: KDE Security Advisories - KDE Community Content of this advisory: 1) security vulnerability resolved: Remote command execution via the lisa lanbrowser. problem description, discussion, solution and upgrade information 2) pending vulnerabilities, solutions, workarounds: problem in KDE rlogin:// URL handler 3) standard appendix (further information) ______________________________________________________________________________ 1) problem description, brief discussion, solution, upgrade information During a security review, the SuSE security team has found two vulnerabilities in the KDE lanbrowsing service. LISa is used to identify CIFS and other servers on the local network, and consists of two main modules: "lisa", a network daemon, and "reslisa", a restricted version of the lisa daemon. LISa can be accessed in KDE using the URL type "lan://", and resLISa using the URL type "rlan://". LISA will obtain information on the local network by looking for an existing LISA server on other local hosts, and if there is one, it retrieves the list of servers from it. If there is no other LISA server, it will scan the network itself. SuSE Linux can be configured to run the lisa daemon at system boot time. The daemon is not started by default, however. The first vulnerability found is a buffer overflow in the lisa daemon, and can be exploited by an attacker on the local network to obtain root privilege on a machine running the lisa daemon. It is not exploitable on a default installation of SuSE Linux, because the lisa daemon is not started by default. The second vulnerability is a buffer overflow in the lan:// URL handler. It can possibly be exploited by remote attackers to gain access to the victim user's account, for instance by causing the user to follow a bad lan:// link in a HTML document. This update provides fixes for SuSE Linux 7.2 and 7.3. Previous updates already corrected the vulnerability in SuSE Linux 8.0, and SuSE Linux 8.1 contains the fix already. 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. Intel i386 Platform: SuSE-7.3: 796ee745cea4f743ba4dc7314d0eab47 source rpm(s): bdbcc6e939e4fb2f67d92c4998550ebe SuSE-7.2: 52168eb8a1f393d5b070e76a40e12040 source rpm(s): d46367f1c45e557a10854ef9efaa6184 Sparc Platform: SuSE-7.3: 0e7fb9026b8fbf8f023bccb6a1ffe9e3 source rpm(s): c11e3cf176d02bf600d312e527ffa159 PPC Power PC Platform: SuSE-7.3: 267805b2368f739ec195bec154b7e04c source rpm(s): 7f52f011e7b7535b0396fe5d00cf04a8 ______________________________________________________________________________ 2) Pending vulnerabilities in SuSE Distributions and Workarounds: In KDE 2.x and KDE 3.x, there is a vulnerability in the handler for rlogin:// URLs, which allows remote attackers to execute arbitrary shell commands with the privileges of the victim user. A similar vulnerability exists in KDE 2.x in the handler for telnet:// URLs. The SuSE KDE team is in the process of preparing a kdelibs update for SuSE Linux. In the interim, we recommend the to disable KDE support for rlogin as a workaround. On KDE 3.0, execute the following command as root: rm /opt/kde3/share/services/rlogin.protocol On KDE 2, execute these commands: rm /opt/kde2/share/services/rlogin.protocol rm /opt/kde2/share/services/telnet.protocol ______________________________________________________________________________ 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>