I. BACKGROUND
The capture program is a setuid root application, installed by default
under multiple versions of IBM AIX, that allows terminal sessions to be
dumped to a file. More information can be found at the following URL.
http://publib.boulder.ibm.com/infocenter/pseries/v5r3/topic/com.ibm.ai
x.cmds/doc/aixcmds1/capture.htm
II. DESCRIPTION
Local exploitation of a stack-based buffer overflow vulnerability in the
'capture' program included with IBM Corp.'s AIX operating system allows
an attacker to execute arbitrary code with root privileges.
The vulnerability exists within the code that parses terminal control
sequences. A long series of control sequences will trigger an
exploitable stack-based buffer overflow.
III. ANALYSIS
Exploitation of this vulnerability results in the execution of arbitrary
code with root privileges.
The capture program is setuid root, and executable by any user with
local access. The vulnerability is a stack-based buffer overflow, and
is trivially exploitable.
IV. DETECTION
iDefense has confirmed the existence of this vulnerability in AIX
version 5.3 with service pack 6. Previous versions may also be
affected.
V. WORKAROUND
Removing the setuid bit from the binary will prevent exploitation, but
may make the program unusable by non-root users.
VI. VENDOR RESPONSE
IBM Corp. has addressed this vulnerability by releasing interim fixes.
More information can be found via the Bulletins tab of IBM's
Subscription Service for UNIX and Linux servers. You can reach this
service by clicking the URL shown below.
http://www14.software.ibm.com/webapp/set2/subscriptions/pqvcmjd?mode=1
VII. CVE INFORMATION
The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CVE-2007-3333 to this issue. This is a candidate for inclusion in
the CVE list (http://cve.mitre.org/), which
standardizes names for
security problems.
VIII. DISCLOSURE TIMELINE
06/05/2007 Initial vendor notification
06/08/2007 Initial vendor response
07/26/2007 Coordinated public disclosure
IX. CREDIT
The discoverer of this vulnerability wishes to remain anonymous.
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X. LEGAL NOTICES
Copyright © 2007 iDefense, Inc.
Permission is granted for the redistribution of this alert electronically. It may not be edited in
any way without the express written consent of iDefense. If you wish to reprint the whole or any
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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, this information.
