Vulnerability Note VU#632633

Wyse Simple Imager (WSI) is a component of Wyse Device Manager (WDM, formerly known as Wyse Rapport). WSI includes TFTPD32 as the TFTP service to load firmware images on client devices. The versions of TFTPD32 contains several known vulnerabilities. The following list of TFTPD32 vulnerabilities is based on public information:

1. CVE-2002-2226 Buffer overflow in tftpd of TFTP32 2.21 and earlier allows remote attackers to execute arbitrary code via a long filename argument.
2. CVE-2002-2237 tftp32 TFTP server 2.21 and earlier allows remote attackers to cause a denial of service via a GET request with a DOS device name such as com1 or aux.
3. CVE-2002-2353 tftpd32 2.50 and 2.50.2 allows remote attackers to read or write arbitrary files via a full pathname in GET and PUT requests.
4. CVE-2006-0328 Format string vulnerability in Tftpd32 2.81 allows remote attackers to cause a denial of service via format string specifiers in a filename in a (1) GET or (2) SEND request.
5. CVE-2006-6141 Buffer overflow in Tftpd32 3.01 allows remote attackers to cause a denial of service via a long GET or PUT request, which is not properly handled when the request is displayed in the title of the gauge window.
6. OSVDB ID: 12898 Tftpd32 contains a flaw that may allow a remote denial of service. The issue is triggered when the server receives a TFTP request with a long filename, and will result in loss of availability for the service.

An attacker with network access to TFTPD32 could execute arbitrary code or cause a denial of service on a vulnerable system.

Use Wyse WDM and USB Imaging Tool

According to Wyse, WSI 1.3.x is a legacy product and its functionality is included in Wyse WDM 4.7.2 and Wyse USB Imaging Tool. Customers are strongly advised to migrate to WDM and USB Imaging Tool. Customers who are unable to migrate promptly, can refer to Wyse Knowledge Base article 18555 for remedial action. Wyse Knowledge Base is accessible through http://suppport.wyse.com/.

Upgrade TFTPD32

Upgrade TFTPD32 by downloading the latest version.

WSI 1.3.6 provides TFTPD32 version 2.0 in the directory ftproot\Rapport\Tools\sa\util\ and TFTPD32 version 2.80 in ftproot\Rapport\Tools\sa\util\TFTPD280\. Consider using TFTPD32 version 2.80 or downloading the most current version of TFTPD32.

This table is based on public information, a brief exchange with the author of TFTPD32, and limited testing. This information may not be completely accurate, please send corrections to cert@cert.org.

Restrict Access to WSI

To limit the exposure of TFTPD32, run WSI systems on a physically isolated network, such as a staging network where client devices are imaged before production deployment..