Alexander O. Yuriev
1996-Nov-22 13:50 UTC
LSF Update#14: Vulnerability of the lpr program.
-----BEGIN PGP SIGNED MESSAGE----- $Id: lpr-vulnerability-0.6-linux,v 1.1 1996/11/22 21:42:46 alex Exp $ Linux Security FAQ Update lpr Vulnerability Thu Nov 21 22:24:12 EST 1996 Copyright (C) 1995,1996 Alexander O. Yuriev (alex@bach.cis.temple.edu) CIS Laboratories TEMPLE UNIVERSITY U.S.A. ============================================================================ This is an official Update of the Linux Security FAQ, and it is supposed to be signed by one of the following PGP keys: 1024/ADF3EE95 1995/06/08 Linux Security FAQ Primary Key <Alexander O. Yuriev> Unless you are able to verify at least one of signatures, please be very careful when following instructions. Linux Security WWW: http://bach.cis.temple.edu/linux/linux-security linux-security & linux-alert mailing list archives: ftp://linux.nrao.edu/pub/linux/security/list-archive ============================================================================ REVISION HISTORY (This section in automatically maintained by the Revision Control System ) $Log: lpr-vulnerability-0.6-linux,v $ Revision 1.1 1996/11/22 21:42:46 alex Initial revision ABSTRACT A vulnerability exists in the lpr program version 0.06. If installed suid to root, the lpr program allows local users to gain access to a super-user account. RISK ASSESSMENT Local users can gain root privileges. The exploits that exercise this vulnerability were made available. VULNERABILITY ANALYSIS lpr utility from the lpr 0.06 suffers from the buffer overrun problem. Installing lpr as a suid-to-root is needed to allow print spooling. DISTRIBUTION FIXES Red Hat Commercial Linux RedHat 2.1, RedHat 3.0.3 (Picasso) and RedHat 4.0 contain vulnerable lpr utility. Users of RedHat Linux distributions prior to version 4.0 are urged to upgrade to RedHat Linux 4.0 The replacement RPMS are available from the following URLs: RedHat 4.0 x86 Architecture ftp://ftp.redhat.com/pub/redhat/redhat-4.0/updates/i386/lpr-0.12-1.i386.rpm ftp://bach.cis.temple.edu/pub/Linux/Security/DISTRIBUTION-FIXES/RedHat/lpr-0.12-1.i386.rpm RedHat 4.0 Alpha Architecture ftp://ftp.redhat.com/pub/redhat/redhat-4.0/updates/axp/lpr-0.12-1.axp.rpm ftp://bach.cis.temple.edu/pub/Linux/Security/DISTRIBUTION-FIXES/RedHat/lpr-0.12-1.axp.rpm RedHat 4.0 SPARC Architecture ftp://ftp.redhat.com/pub/redhat/redhat-4.0/updates/sparc/lpr-0.12-1.sparc.rpm ftp://bach.cis.temple.edu/pub/Linux/Security/DISTRIBUTION-FIXES/RedHat/lpr-0.12-1.sparc.rpm Please verify the MD5 fingerprint of the RPMs prior to installing them. 6d36461d6c8b6c50ccadf9de530a6136 lpr-0.12-1.i386.rpm 87eb9c5b4d7e6a4217fdb9d3bbd6527b lpr-0.12-1.axp.rpm c04359e61cd16108ce5793aa388f206f lpr-0.12-1.sparc.rpm Caldera Network Desktop Caldera Network Desktop version 1.0 contains a vulnerable lpr program. The replacement RPMS are available from the following URLs: ftp://ftp.caldera.com/pub/cnd-1.0/updates/NetKit-B-lpr-0.06-4c2.i386.rpm ftp://bach.cis.temple.edu/pub/Linux/Security/DISTRIBUTION-FIXES/CND/NetKit-B-lpr-0.06-4c2.i386.rpm WARNING: We are unable to provide the MD5 fingerprint for the replacement kit from Caldea as it was not provided to us. Debian Debian/GNU Linux 1.1 does not use lpr program and therefore is not vulnerable. If you have installed lpr package yourself, your system becomes vulnerable. Slackware There is no official information available about vulnerability of Slackware 3.0 or Slackware 3.1 distributions from distribution maintainer. The testing indicates that both Slackware 3.0 and Slackware 3.1 distributions contains the vulnerable lpr program. Until the official fix-kit for Slackware 3.0 and Slackware 3.1 available system administrators are advised to follow the instructions in the Other Linux Distributions section of this LSF Update. Yggdrasil Yggdrasil Computing Inc neither confirmed not denied vulnerability of Plug and Play Fall''95 Linux. The testing indicates that Plug and Play Fall''95 Linux distribution contains a vulnerable lpr. Until the official fix-kit for Yggdrasil Plug and Play Linux becomes available system administrators are advised to follow the instructions in the Other Linux Distributions section of this LSF Update Other Linux Distributions It is believed at this moment that all Linux distributions using lpr version 0.06 or prior contain a vulnerable lpr program. Administrators of systems based on distributions not listed in this update or distributions that do not have fix-kits available at the moment are urged to contact their support centers requesting the fix-kits to be made available to them. In order to prevent the vulnerability from being exploited in the mean time, it is recommended that the suid bit is removed from the lpr program using command chmod u-s /usr/bin/lpr Until the official fix-kits are available for those systems, it is advised that system administrators obtain the source code of a LPRng print system used in Debian/GNU Linux 1.1, compile it and replace the lpr subsystem. ftp://ftp.debian.org/debian/project/experimental/lprng_2.3.12.orig.tar.gz ftp://ftp.debian.org/debian/project/experimental/lprng_2.3.12-2.diff.gz ftp://bach.cis.temple.edu/pub/Linux/Security/DISTRIBUTION-FIXES/OTHER/lprng_2.3.12.orig.tar.gz ftp://bach.cis.temple.edu/pub/Linux/Security/DISTRIBUTION-FIXES/OTHER/lprng_2.3.12-2.diff.gz Please verify the MD5 fingerprint of the files prior to installing them. ca51aaa4560ddfc6ced987d568d8cc1c lprng_2.3.12-2.diff.gz f1c23e214a752e1c2dab2399b3457d2d lprng_2.3.12.orig.tar.gz CREDITS This LSF Update is based on the information originally posted to linux-security mailing list. The information on the fix-kit for Red Hat commercial Linux was provided by Marc Ewing (marc@redhat.com) of Red Hat Software Inc,; for the Caldera Network Desktop by Ron Holt of Caldera Inc.; for Debian/GNU Linux 1.1 by Sven Rudolph <sr1@inf.tu-dresden.de> of Debian Project. -----BEGIN PGP SIGNATURE----- Version: 2.6.2 iQCVAwUBMpYbw4xFUz2t8+6VAQF9pgQAhwl4zNBrlfVxgv7+Ubm8uRkRRaZcjvxH 4F4FdFdtBjyqgkj4dMIKEEhy28TZbAqh0ks6eiviwFAYuMnu3G+MBeGLyHOpX4Mw krb7At3wt41Yj5NXHpsz9GebYBVfM8sOl4CKX0UcdXdizxfNKxXd8SJLnYteye2b 8paVHnyyDyo=9xvg -----END PGP SIGNATURE-----