Hewlett-Packard HP-UX SLSd Arbitrary File Creation Vulnerability

iDefense Security Advisory 02.13.07
http://labs.idefense.com/intelligence/vulnerabilities/
Feb 13, 2007

I. BACKGROUND

Hewlett-Packard's HP-UX introduced "Single Logical Screen" (SLS) in 1995 to
facilitate using multiple graphics devices on a single desktop. Distributed
SLS, or SLS/d, extends SLS to allow the utilization of graphics devices
within multiple computer systems. More information is available at the
following URL.

http://docs.hp.com/en/B2355-90142/ch05s03.html

II. DESCRIPTION

Remote exploitation of a design error within Hewlett-Packard's "SLSd" daemon
could allow an attacker to execute privileges as the superuser.

The problem specifically exists due to a design error within the
"SLSd_daemon" RPC daemon that provides connectivity between the
distributed systems. This daemon registers itself under the RPC PROGID of
536870913 or 351456, depending on the HP-UX version. By sending a
specially crafted request, the daemon will write attacker supplied data to
an arbitrary file as the superuser.

III. ANALYSIS

Exploitation allows an unauthenticated attacker to gain superuser
privileges by overwriting select files such as .rhosts, cron scripts, or
other files used for authentication.

IV. DETECTION

iDefense has confirmed the existence of this vulnerability within the
"SLSd_daemon" binary as shipped with HP-UX 11.11i and 10.20. All versions
are suspected to be vulnerable.

V. WORKAROUND

Employ firewalls to limit access to the affected system to reduce exposure
to this vulnerability. If you are not using Distrubuted SLS, disable the
SLSd_daemon.

VI. VENDOR RESPONSE

Hewlett-Packard has addressed this vulnerabilty with HP Security Advisory
HPSBUX02191. More information is available at the following URL.

http://www1.itrc.hp.com/service/cki/docDisplay.do?docId=c00862809

VII. CVE INFORMATION

A Mitre Corp. Common Vulnerabilities and Exposures (CVE) number has not
been assigned yet.

VIII. DISCLOSURE TIMELINE

01/30/2007  Initial vendor notification
01/30/2007  Initial vendor response
02/13/2007  Coordinated public disclosure

IX. CREDIT

The discoverer of this vulnerability wishes to remain anonymous.

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X. LEGAL NOTICES

Copyright © 2006 iDefense, Inc.

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Disclaimer: The information in the advisory is believed to be accurate at
the time of publishing based on currently available information. Use of
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