Airscanner Mobile Security Advisory #05081102: vxFtpSrv 0.9.7 Remote Code Execution Buffer Overflow Vulnerability
Airscanner Mobile Security Advisory #05081102:
vxFtpSrv 0.9.7 Remote Code Execution Buffer Overflow Vulnerability
Product:
vxFtpSrv 0.9.7
Platform:
Tested on Windows Mobile Pocket PC 2003
Requirements:
Mobile device running Windows Mobile Pocket PC with vxFtpSrv 0.9.7 installed
and running.
Credits:
Seth Fogie
Airscanner Mobile Security
http://www.airscanner.com
Mobile Antivirus Researchers Association
http://www.mobileav.org
August 12 2005
Risk Level:
High. Remote attacker can execute code.
Summary:
vxFtpSrv is a complete multi-threaded FTP server for Windows CE-based Handheld
Pro, Pocket PC, Pocket PC 2002 and Windows Mobile 2003 devices. If an
excessively long user name is provided, a buffer overflow will occur, thus
causing either an instant crash of the program or code execution.
Details:
USER seth@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@J@@@I@@@H@@@G@@@F@@@E@
@@D@@@C@@@B@@@XXXX where XXXX represents the address of the return address that
will be loaded into the Program Counter.
The bug is found in an sprintf function responsible for writing back a password
request to the user. If the user provided name is excessively long, a buffer
overflow will occur. Remote code execution is possible, assuming the attacker
can guess what memory segment the program is located in. Generally, this will
be 18,20,22, or 24.
Workaround:
None
Vendor Response:
Waiting response.
Copyright (c) 2005 Airscanner Corp.
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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 the
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publisher accepts any liability for any direct, indirect, or consequential loss
or damage arising from use of, or reliance on, this information.
advisory
http://www.airscanner.com/security/05081102_vxftpsrv.htm