Airscanner Mobile Security Advisory #05081203:
vxTftpSrv 1.7.0 Remote Code Execution Buffer Overflow Vulnerability 

Product:
vxTftpSrv 1.7.0

Platform:
Tested on Windows Mobile Pocket PC 2003

Requirements:
Mobile device running Windows Mobile Pocket PC with vxTFTPSrv 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:
vxTftpSrv is a simple, easy to use, Trivial File Transfer Protocol Server (TFTP) program which can be used to transfer files to and from routers, switches, hubs and other network devices. vxTftpSrv is typically used by Network Administrators to configure such equipment. Due to a improperly checked strcat call, it is possible to injection and execute code remotely via a buffer overflow.

Details:
When a long file name (>512 bytes) is sent to the tftp server, a strcat function overflows the stack. When the subroutine is complete, the Program Counter is loaded from the stack, which results in a crash or remote code execution depending on the contents of the injected file name. 

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 information constitutes acceptance for use on 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.

http://www.airscanner.com/security/05081203_vxtftpsrv.htm