______________________________________________________________________________ SuSE Security Announcement Package: xli/xloadimage Announcement-ID: SuSE-SA:2001:024 Date: Tuesday, July 24th 2001 17:30 MEST Affected SuSE versions: (6.0, 6.1, 6.2,) 6.3, 6.4, 7.0, 7.1, 7.2 Vulnerability Type: remote system compromise Severity (1-10): 3 SuSE default package: no Other affected systems: yes Content of this advisory: 1) security vulnerability resolved: xli problem description, discussion, solution and upgrade information 2) pending vulnerabilities, solutions, workarounds 3) standard appendix (further information) ______________________________________________________________________________ 1) problem description, brief discussion, solution, upgrade information xli, aka xloadimage, a image viewer for X11 is used by Netscape's plugger to display TIFF-, PNG- and Sun-Raster-images. The plugger configuration file is /etc/pluggerrc. Due to missing boundary checks in the xli code a buffer overflow could be triggered by an external attacker to execute commands on the victim's system. An exploit is publically available. SuSE Linux is not vulnerable by default because of the different names. On SuSE Linux the command is called xli, while the plugger uses xloadimage. /etc/pluggerrc: exits: xloadimage -quiet -windowid $window $file If you have xloadimage installed on your system on your own, you should comment out the lines in /etc/pluggerrc, that contain xloadimage, for a temporary fix. Otherwise update the packages for your system. Nevertheless, it's recommended to leave the xloadimage entry in /etc/pluggerrc commented out, because of the potential risk the xloadimage code causes. i386 Intel Platform: SuSE-7.2 d35b3ee5b02bfb1bf4f9d8ccefdfa889 source rpm: 56b928a28cb32cc0103bfa89e74eee05 SuSE-7.1 5216c3ebdbd327506790107a927a0c2e source rpm: c3ee309a35fdcf0652626f9712771523 SuSE-7.0 dffbd8a0c19d8df8141d4434107fb042 source rpm: 410666ff06b1d050fd9cd6a16b190143 SuSE-6.4 8132e176e41d403978049345941679a0 source rpm: d40dc2e9b46b7a9818cfd73dac269758 SuSE-6.3 b7cb7b57c78d8d5b765941372d7d7559 source rpm: f8c47e0de4bfd59b40b0271aca133e36 Sparc Platform: SuSE-7.1 7df3b152cf2e5e89582007fbeb59ec4c source rpm: c110d3e3bfbc73f2a37cb91d468acd60 SuSE-7.0 62d0e49f02a6c6491f1341a6f92aa3b0 source rpm: 00201403e740d408f20e8ae77a63f77f AXP Alpha Platform: SuSE-7.1 fdc3bb5cd102fa3007c3fe5fb0ae999b source rpm: 72e51e76005f216ea476ff0e2a9890ce SuSE-7.0 ba9efef4991ebc8fda02f00395468468 source rpm: e4d369fd4080965f9a81ba5e97934245 SuSE-6.4 2d37a2be14760c8f3f251c83e141502f source rpm: 8abca3e1af92ccfea799c3b1da6f333e SuSE-6.3 76f134e228a39a440c517a3dc673b250 source rpm: 88dbb49098cc0120e72b4ac4b357c1d8 PPC Power PC Platform: SuSE-7.1 52df89afc2aef3752bc968b7e179e85b source rpm: 00d53cae7c9d856069f720abb746c173 SuSE-7.0 065b0453669abfad9d7afd51f9712c22 source rpm: ppc/update/7.0/zq1/xli-1.16-304.src.rpm d536054cff521e6f62cc01ef16f910ce SuSE-6.4 efbd1b48104f53cef252d3e40918303c source rpm: 310f59a98f63b78d8d3f528aa85546c2 ______________________________________________________________________________ 2) Pending vulnerabilities in SuSE Distributions and Workarounds: - dqs dex@raza-mexicana.org has found an exploitable buffer overflow bug in the dsh program from the dqs package on SuSE Linux distributions. To workaround the problem, do "chmod -s /usr/bin/dsh" and change the files /etc/permissions* to reflect the change. If you do not need the dqs package, then deinstall it (rpm -e dqs). Packages for most of the supported SuSE Linux distributions are available at the usual location/ for download and installation/update. Do not forget to change the files /etc/permissions* to remove the suid-bit from the dsh program. Please note that we will not issue a dedicated security announcement for this specific bug. - pcp Paul Starzetz discovered a security weakness in the setuid root program /usr/share/pcp/bin/pmpost. The common library in pcp trusts the environment that has been supplied by the user, regardless of privileged execution or not. By consequence, a user can specify the configuration file and therefore write to files owned by root. The problem is not based on insecurely following symlinks as stated by Paul Starzetz. The pcp package is not installed by default in SuSE Linux distributions. We have provided update packages for the SuSE Linux distributions version 7.1 and 7.2 that remove the setuid bit from the pmpost binary. Versions before SuSE-7.1 were not affected because the setuid bit was not set. We thank Keith Owens and Mark Goodwin from Silicon Graphics for responding quickly and for publishing a new version of the pcp package which will be included in future releases of the SuSE Linux distribution. For more information see the /usr/share/doc/packages/pcp directory of your SuSE Linux installation after installing the update package, or go to obtained from . Please note that there will not be a dedicated security announcement for this specific bug. - fetchmail (fetchml) New fetchmail packages are available on the ftp server. The packages cure a buffer overflow that can be exploited by sending a victim a specially designed email, waiting for the victim's fetchmail program to pick up the email. We are preparing a security announcement for this problem. - openssh update packages for the openssh package after (and including) SuSE-6.4 are available on our ftp servers ftp.suse.de (for <7.1) (for ftp.suse.com or>= 7.1). We are currently checking for a non-security related irregularity in sshd's behaviour under faulty setup conditions. - exim SuSE Linux distributions do not contain the exim Mail Transport Agent (See Exim Internet Mailer for details) and are therefore not susceptible to the recently found security-related bugs. - webmin SuSE Linux distributions do not contain the webmin administration web frontend (See https://www.webmin.org/ for details) and are therefore not vulnerable to the recently found security-related problems in the software. ______________________________________________________________________________ 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 md5sum after 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 7.1)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 uninstalled 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 toplevel 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 annoucements 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>. The <security@suse.com> 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 cleartext signature shows proof of the authenticity of the text. SuSE GmbH makes no warranties of any kind whatsoever with respect to the information contained in this security advisory.