CERT-SEI

HP-UX Line Printer Daemon Vulnerable to Directory Traversal

Original release date: November 21, 2001
Last revised: December 6, 2001
Source: CERT/CC

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

Systems Affected

HP9000 Servers running the following releases:
  • HP-UX Version 10.01
  • HP-UX Version 10.10
  • HP-UX Version 10.20
  • HP-UX Version 11.00
  • HP-UX Version 11.11

Overview

The HP-UX line printer daemon (rlpdaemon) enables various clients to share printers over a network. A remotely exploitable directory traversal vulnerability exists in the rlpdaemon.

I. Description

By sending a specially crafted print request to an HP-UX host running the rlpdaemon, a local or remote attacker can create arbitrary files or directories on the target host. Given the ability to create files on the system, an attacker may be able to leverage this vulnerability to gain privileged access to the system. Intruders may find this vulnerability attractive to exploit because the line printer daemon is enabled by default to provide printing services. Additionally, no previous knowledge of or access to the vulnerable system is required for exploitation.

Internet Security Systems (ISS) and Hewlett-Packard Company have issued the following announcements, respectively:

Remote Logic Flaw Vulnerability in HP-UX Line Printer Daemon
Hewlett-Packard Company Security Bulletin #0176

This vulnerability has been assigned the identifier CAN-2001-0817 by the Common Vulnerabilities and Exposures (CVE) group:

http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2001-0817


For the latest and most detailed information about this vulnerability, please see VU#638011.

II. Impact

An attacker may be able to gain priviledged access and execute arbitrary code on the target system.

III. Solution

Install a patch from HP. More information is available in Appendix A.

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 until a patch can be applied. 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. When vendors report new information to the CERT/CC, we 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.

Hewlett-Packard Company

Please see Hewlett-Packard Company Security Bulletin #0176.

Appendix B. - References

  1. http://www.kb.cert.org/vuls/id/638011
  2. http://xforce.iss.net/alerts/advise102.php
  3. http://www.kb.cert.org/vuls/id/IAFY-54PKL4


This vulnerability was discovered and researched by Mark Dowd and Kris Hunt of Internet Security Systems (ISS). The CERT/CC thanks ISS for the information contained in their advisory.


Author: Ian A. Finlay.

Copyright 2001 Carnegie Mellon University.

Revision History

November 21, 2001: initial release
December 06, 2001: changed title, updated description, updated impact