[原文]gr_osview in SGI IRIX 6.5.22, and possibly other 6.5 versions, does not drop privileges when opening description files while in debug mode, which allows local users to read a line from arbitrary files via the -d and -D options, which prints the line as a formatting error.
iDEFENSE Security Advisory 04.07.05 - Local exploitation of an information disclosure vulnerability in the gr_osview command included in multiple versions of Silicon Graphics Inc.'s IRIX Operating System could allow for the disclosure of sensitive information such as the root user's password hash. The vulnerability specifically exists in the way that gr_osview opens user-specified description files without dropping privileges. When this is combined with the debug option, it is possible to dump a line from an arbitrary file, regardless of its protection.
SGI IRIX gr_osview Information Disclosure Vulnerability
iDEFENSE Security Advisory 04.07.05
April 7, 2005
The gr_osview application is a setuid root application that provides a
graphical display of usage of certain types of operating system
resources. It is installed by default under multiple versions of IRIX 6.
Local exploitation of an information disclosure vulnerability in the
gr_osview command included in multiple versions of Silicon Graphics
Inc.'s IRIX Operating System could allow for the disclosure of sensitive
information such as the root user's password hash.
The vulnerability specifically exists in the way that gr_osview opens
user-specified description files without dropping privileges. When this
is combined with the debug option, it is possible to dump a line from an
arbitrary file, regardless of its protection. An example is as follows:
user@irix$ gr_osview -d -D /etc/shadow
sgets: waiting for string
*SR> read <root:PASSWDHASHHERE:2051::::::>
gr_osview: description file format error on line 1
To elevate privileges, the attacker would then have to crack the root
password using the acquired hash.
All that is required to exploit this vulnerability is a local account
and an open X display, which could be the attacker's home machine or
another compromised computer. Exploitation does not require any
knowledge of application internals, making exploitation trivial, even
for unskilled attackers. The most effective exploitation method would be
reading the first line of the operating system shadow file and then
attempting to crack the root password hash. If successful, this would
lead to a full root compromise.
iDEFENSE has confirmed the existence of this vulnerability in SGI IRIX
version 6.5.22 (maintenance). It is suspected that previous and later
versions of both the feature and maintenance revisions of IRIX 6.5 are
Only allow trusted users local access to security-critical systems.
Alternately, remove the setuid bit from inpview using:
chmod u-s /usr/sbin/gr_osview
VI. VENDOR RESPONSE
This vulnerability has been addressed in SGI BUG 930892.
Related security advisories are available at:
Related patches are available at:
VII. CVE INFORMATION
The Common Vulnerabilities and Exposures (CVE) project has assigned the
names CAN-2005-0464 to these issues. This is a candidate for inclusion
in the CVE list (http://cve.mitre.org), which standardizes names for
VIII. DISCLOSURE TIMELINE
02/18/2005 Initial vendor notification
02/23/2005 Initial vendor response
04/07/2005 Coordinated public disclosure
The discoverer of this vulnerability wishes to remain anonymous.
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X. LEGAL NOTICES
Copyright (c) 2005 iDEFENSE, Inc.
Permission is granted for the redistribution of this alert
electronically. It may not be edited in any way without the express
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email firstname.lastname@example.org for permission.
Disclaimer: The information in the advisory is believed to be accurate
at the time of publishing based on currently available information. Use
of the information constitutes acceptance for use in an AS IS condition.
There are no warranties with regard to this information. Neither the
author nor the publisher accepts any liability for any direct, indirect,
or consequential loss or damage arising from use of, or reliance on,
IRIX contains a flaw that may lead to an unauthorized information disclosure. The issue is triggered when permissions are not correctly verified when opening description files using gr_osview, which will disclose the first line of arbitrary files via the "-d" and "-D" options, resulting in a loss of confidentiality.
Currently, there are no known workarounds or upgrades to correct this issue. However, IRIX has released patches to address this vulnerability.
gr_osview is reported prone to an information disclosure vulnerability. This issue can help a local attacker to obtain sensitive information such as exposing an administrator's password hash and carrying out other attacks.
This issue has been confirmed in SGI IRIX 6.5.22 maintenance release. Other versions of IRIX may be vulnerable as well.
An exploit is not required.
The following proof of concpet is available: gr_osview -d -D /etc/shadow
It is reported that the vendor has acknowledged this issue and released patches to address it. This cannot be confirmed at the moment. Please contact the vendor for more information.
Currently we are not aware of any vendor-supplied patches for this issue. If you feel we are in error or are aware of more recent information, please mail us at: email@example.com <mailto:firstname.lastname@example.org>.