CERT Advisory CA-2001-30 Multiple Vulnerabilities in lpd

From: CERT Advisory (cert-advisory@cert.org)
Date: 11/05/01


Date: Mon, 5 Nov 2001 14:29:27 -0500 (EST)
Message-Id: <CA-2001-30.1@cert.org>
From: CERT Advisory <cert-advisory@cert.org>
To: cert-advisory@cert.org
Subject: CERT Advisory CA-2001-30 Multiple Vulnerabilities in lpd


-----BEGIN PGP SIGNED MESSAGE-----

CERT Advisory CA-2001-30 Multiple Vulnerabilities in lpd

   Original release date: November 05, 2001
   Last revised: --
   Source: CERT/CC

   A complete revision history can be found at the end of this file.

Systems Affected

     * BSDi BSD/OS Version 4.1 and earlier
     * Debian GNU/Linux 2.1 and 2.1r4
     * FreeBSD All released versions FreeBSD 4.x, 3.x, FreeBSD
       4.3-STABLE, 3.5.1-STABLE prior to the correction date
     * Hewlett-Packard HP9000 Series 700/800 running HP-UX releases
       10.01, 10.10, 10.20, 11.00, and 11.11
     * IBM AIX Versions 4.3 and AIX 5.1
     * Mandrake Linux Versions 6.0, 6.1, 7.0, 7.1
     * NetBSD 1.5.2 and earlier
     * OpenBSD Version 2.9 and earlier
     * Red Hat Linux 6.0 all architectures
     * SCO OpenServer Version 5.0.6a and earlier
     * SGI IRIX 6.5-6.5.13
     * Sun Solaris 8 and earlier
     * SuSE Linux Versions 6.1, 6.2, 6.3, 6.4, 7.0, 7.1, 7.2

Overview

   There are multiple vulnerabilities in several implementations of the
   line printer daemon (lpd). The line printer daemon enables various
   clients to share printers over a network. Review your configuration to
   be sure you have applied all relevant patches. We also encourage you
   to restrict access to the lpd service to only authorized users.

I. Description

   There are multiple vulnerabilities in several implementations of the
   line printer daemon (lpd), affecting several systems. Some of these
   problems have been publicly disclosed previously. However, we believe
   many system and network administrators may have overlooked one or more
   of these vulnerabilities. We are issuing this document primarily to
   encourage system and network administators to check their systems for
   exposure to each of these vulnerabilities, even if they have addressed
   some lpd vulnerabilities recently.

   Most of these vulnerabilities are buffer overflows allowing a remote
   intruder to gain root access to the lpd server. For the latest and
   most detailed information about the known vulnerabilities, please see
   the vulnerability notes linked to below.

 VU#274043 - BSD line printer daemon buffer overflow in displayq()

   There is a buffer overflow in several implementations of in.lpd, a BSD
   line printer daemon. An intruder can send a specially crafted print
   job to the target and then request a display of the print queue to
   trigger the buffer overflow. The intruder may be able use this
   overflow to execute arbitrary commands on the system with superuser
   privileges.

   The line printer daemon must be enabled and configured properly in
   order for an intruder to exploit this vulnerability. This is, however,
   trivial as the line printer daemon is commonly enabled to provide
   printing functionality. In order to exploit the buffer overflow, the
   intruder must launch his attack from a system that is listed in the
   "/etc/hosts.equiv" or "/etc/hosts.lpd" file of the target system.

 VU#388183 - IBM AIX line printer daemon buffer overflow in
                 kill_print()

   A buffer overflow exists in the kill_print() function of the line
   printer daemon (lpd) on AIX systems. An intruder could exploit this
   vulnerability to obtain root privileges or cause a denial of service
   (DoS). The intruder would need to be listed in the victim's
   /etc/hosts.lpd or /etc/hosts.equiv file, however, to exploit this
   vulnerability.

 VU#722143 - IBM AIX line printer daemon buffer overflow in
                 send_status()

   A buffer overflow exists in the send_status() function of the line
   printer daemon (lpd) on AIX systems. An intruder could exploit this
   vulnerability to obtain root privileges or cause a denial of service
   (DoS). The intruder would need to be listed in the victim's
   /etc/hosts.lpd or /etc/hosts.equiv file, however, to exploit this
   vulnerability.

 VU#466239 - IBM AIX line printer daemon buffer overflow in chk_fhost()

   A buffer overflow exists in the chk_fhost() function of the line
   printer daemon (lpd) on AIX systems. An intruder could exploit this
   vulnerability to obtain root privileges or cause a denial of service
   (DoS). The intruder would need control of the DNS server to exploit
   this vulnerability.

 VU#39001 - line printer daemon allows options to be passed to sendmail

   There exists a vulnerability in the line printer daemon that permits
   an intruder to send options to sendmail. These options could be used
   to specify another configuration file allowing an intruder to gain
   root access.

 VU#30308 - line printer daemon hostname authentication bypassed with
              spoofed DNS

   A vulnerability exists in the line printer daemon (lpd) shipped with
   the printer package for several systems. The authentication method was
   not thorough enough. If a remote user was able to control their own
   DNS so that their IP address resolved to the hostname of the print
   server, access would be granted when it should not be.

 VU#966075 - Hewlett-Packard HP-UX line printer daemon buffer overflow

   A buffer overflow exists in HP-UX's line printer daemon (rlpdaemon)
   that may allow an intruder to execute arbitrary code with superuser
   privilege on the target system. The rlpdaemon is installed by default
   and is active even if it is not being used. An intruder does not need
   any prior knowledge, or privileges on the target system, in order to
   exploit this vulnerability.

II. Impact

   All of these vulnerabilities can be exploited remotely. In most cases,
   they allow an intruder to execute arbitrary code with the privileges
   of the lpd server. In some cases, an intruder must have access to a
   machine listed in /etc/hosts.equiv or /etc/hosts.lpd, and in some
   cases, an intruder must be able to control a nameserver.

   One vulnerability (VU#39001) allows you to specify options to sendmail
   that can be used to execute arbitrary commands. Ordinarily, this
   vulnerability is only exploitable from machines that are authorized to
   use the lpd server. However, in conjunction with another vulnerability
   (VU#30308), permitting intruders to gain access to the lpd service,
   this vulnerability can be used by intruders not normally authorized to
   use the lpd service.

   For specific information about the impacts of each of these
   vulnerabilities, please consult the CERT Vulnerability Notes Database
   (http://www.kb.cert.org/vuls).

III. Solution

Apply a patch from your vendor

   Appendix A contains information provided by vendors for this advisory.
   As vendors report new information to the CERT/CC, we will update this
   section and note the changes in our revision history. If a particular
   vendor is not listed below, we have not received their comments.
   Please contact your vendor directly.

   This table represents the status of each vendor with regard to each
   vulnerability. Please be aware that vendors produce multiple products;
   if they are listed in this table, not all products may be affected. If
   a vendor is not listed in the table below, then their status should be
   considered unknown. For specific information about the status of each
   of these vulnerabilities, please consult the CERT Vulnerability Notes
   Database (http://www.kb.cert.org/vuls).

+ = Affected
- - = Not Affected
? = Unknown
   
VU# -> |274043 |388183 |722143 |466239 |39001 |30308 |966075
Vendors ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Apple | - | ? | ? | ? | ? | ? | -
BSDI | + | ? | ? | ? | ? | ? | ?
Caldera | - | - | - | - | - | - | -
Cray | ? | - | - | - | - | ? | -
Debian | ? | ? | ? | ? | + | + | ?
Engarde | - | - | - | - | - | - | -
FreeBSD | + | - | - | - | - | - | -
Fujitsu | - | - | - | - | - | - | -
HP | ? | ? | ? | ? | ? | ? | +
IBM | - | + | + | + | - | + | -
Mandrake| ? | ? | ? | ? | + | ? | ?
NetBSD | + | ? | ? | ? | ? | ? | ?
OpenBSD | + | ? | ? | ? | ? | ? | ?
Red Hat | ? | ? | ? | ? | + | + | ?
SCO | + | ? | ? | ? | ? | ? | ?
SGI | + | ? | ? | ? | ? | ? | ?
SuSE | + | ? | ? | ? | ? | ? | ?
Sun | - | - | - | - | + | - | -

Restrict access to the lpd service

   As a general practice, we recommend disabling all services that are
   not explicitly required. You may wish to disable the line printer
   daemon if there is not a patch available from your vendor.

   If you cannot disable the service, you can limit your exposure to
   these vulnerabilities by using a router or firewall to restrict access
   to port 515/TCP (printer). Note that this does not protect you against
   attackers from within your network.

Appendix A. - Vendor Information

   This appendix contains information provided by vendors for this
   advisory. As vendors report new information to the CERT/CC, we will
   update this section and note the changes in our revision history. If a
   particular vendor is not listed below, we have not received their
   comments.

Apple Computer, Inc.

   Mac OS X does not have the line printer daemon vulnerability issues
   described in these advisories.

Berkeley Software Design, Inc. (BSDI)

   Some (older) versions are affected. The current (BSD/OS 4.2) release
   is not vulnerable. Systems are only vulnerable to attack from hosts
   which are allowed via the /etc/hosts.lpd file (which is empty as
   shipped).
   BSD/OS 4.1 is the only vulnerable version which is still officially
   supported by Wind River Systems. A patch (M410-044) is available in
   the normal locations, ftp://ftp.bsdi.com/bsdi/patches or via our web
   site at http://www.bsdi.com/support

Compaq

   Compaq has not been able to reproduce the problems identified in this
   advisory for TRU64 UNIX. We will continue testing and address the LPD
   issues if a problem is discovered and provide patches as necessary.

Cray

   Cray, Inc. has been unable to prove an lpd vulnerability. However, it
   was deemed that a buffer overflow may be possible and so did tighten
   up the code. See Cray SPR 721101 for more details.

Debian

   http://www.debian.org/security/2000/20000109

FreeBSD, Inc.

 ftp://ftp.freebsd.org/pub/FreeBSD/CERT/advisories/FreeBSD-SA-01%3A58.lpd.asc

Hewlett-Packard Company

   Hewlett-Packard has released
   HPSBUX0108-163 Sec. Vulnerability in rlpdaemon
   Bulletin and patches available from http://itrc.hp.com
   Details to access http://itrc.hp.com are include at the last half of
   any HP Bulletin.

IBM Corporation

 http://www-1.ibm.com/services/continuity/recover1.nsf/4699c03b46f2d4f68525678c006d45ae/85256a3400529a8685256ac7005cf00a/$FILE/oar391.txt

Mandrake Software

   http://www.linux-mandrake.com/en/updates/2000/MDKSA-2000-054.php3

NetBSD

   If lpd has been enabled, this issue affects NetBSD versions 1.5.2 and
   prior releases, and NetBSD-current prior to August 30, 2001. lpd is
   disabled by default in NetBSD installations.
   
   Detailed information will be released subsequent to the publication of
   this CERT advisory.
   
   An up-to-date PGP signed copy of the release will be maintained at

   ftp://ftp.netbsd.org/pub/NetBSD/security/advisories/NetBSD-SA2001-018.txt.asc
   
   Information about NetBSD and NetBSD security can be found at
   http://www.NetBSD.ORG and http://www.NetBSD.ORG/Security/.

OpenBSD

   http://www.openbsd.org/errata29.html#lpd

RedHat Inc.

   http://www.redhat.com/support/errata/RHSA2000002-01.6.0.html

Santa Cruz Operation, Inc. (SCO)

   ftp://stage.caldera.com/pub/security/openserver/CSSA-2001-SCO.20/

SGI

   ftp://patches.sgi.com/support/free/security/advisories/20011003-01-P

SuSE

 http://lists2.suse.com/archive/suse-security-announce/2001-Oct/0000.html
     _________________________________________________________________

   The CERT Coordination Center thanks Internet Security Systems and IBM
   for the information provided in their advisories.
     _________________________________________________________________

   Feedback on this document can be directed to the author,
   Jason A. Rafail
     _________________________________________________________________

   References
     * http://www.kb.cert.org/vuls/id/274043
     * http://www.kb.cert.org/vuls/id/388183
     * http://www.kb.cert.org/vuls/id/722143
     * http://www.kb.cert.org/vuls/id/466239
     * http://www.kb.cert.org/vuls/id/39001
     * http://www.kb.cert.org/vuls/id/30308
     * http://www.kb.cert.org/vuls/id/966075
     * http://www.kb.cert.org/vuls
   ______________________________________________________________________

   This document is available from:
   http://www.cert.org/advisories/CA-2001-30.html
   ______________________________________________________________________

CERT/CC Contact Information

   Email: cert@cert.org
          Phone: +1 412-268-7090 (24-hour hotline)
          Fax: +1 412-268-6989
          Postal address:
          CERT Coordination Center
          Software Engineering Institute
          Carnegie Mellon University
          Pittsburgh PA 15213-3890
          U.S.A.

   CERT/CC personnel answer the hotline 08:00-17:00 EST(GMT-5) /
   EDT(GMT-4) Monday through Friday; they are on call for emergencies
   during other hours, on U.S. holidays, and on weekends.

Using encryption

   We strongly urge you to encrypt sensitive information sent by email.
   Our public PGP key is available from

   http://www.cert.org/CERT_PGP.key

   If you prefer to use DES, please call the CERT hotline for more
   information.

Getting security information

   CERT publications and other security information are available from
   our web site

   http://www.cert.org/

   To subscribe to the CERT mailing list for advisories and bulletins,
   send email to majordomo@cert.org. Please include in the body of your
   message

   subscribe cert-advisory

   * "CERT" and "CERT Coordination Center" are registered in the U.S.
   Patent and Trademark Office.
   ______________________________________________________________________

   NO WARRANTY
   Any material furnished by Carnegie Mellon University and the Software
   Engineering Institute is furnished on an "as is" basis. Carnegie
   Mellon University makes no warranties of any kind, either expressed or
   implied as to any matter including, but not limited to, warranty of
   fitness for a particular purpose or merchantability, exclusivity or
   results obtained from use of the material. Carnegie Mellon University
   does not make any warranty of any kind with respect to freedom from
   patent, trademark, or copyright infringement.
     _________________________________________________________________

   Conditions for use, disclaimers, and sponsorship information

   Copyright 2001 Carnegie Mellon University.

   Revision History
November 05, 2001: Initial release

-----BEGIN PGP SIGNATURE-----
Version: PGP 6.5.8

iQCVAwUBO+boKKCVPMXQI2HJAQFLWgP/R8K+kw9GrKp0rF5hdrsiowPOBaO716OM
M4dRX+5Ek+svlY9/P948FfU4CyKG1c4M9FzSMgoKTUmvsnB+NVFgln/d0+jMfAy0
IyzHxyp5bSbF6pbfEyyr7gy8S3xaaVyDbAmhuLAW0Kiwy1xMmOFjZLu0W+A99rf7
XMm+KQhJe6o=
=pB53
-----END PGP SIGNATURE-----



Relevant Pages