_______________________________________________________________________ Rapid7, LLC Security Advisory _______________________________________________________________________ Rapid7 Advisory R7-0019 Directory traversal vulnerability in SolarWinds TFTP Server for Windows Date: April 21, 2006 Revision: 1.0 http://www.rapid7.com/advisories/R7-0019.html CVE: CVE-2006-1951 1. Affected system(s): KNOWN VULNERABLE: o SolarWinds TFTP Server v8.1 and earlier KNOWN FIXED: o SolarWinds TFTP Server v8.2 2. Summary Rapid7 has found a directory traversal vulnerability in SolarWinds TFTP Server for Windows. This vulnerability allows remote users to download any files outside of the server's TFTP data directory. 3. Vendor status and information SolarWinds http://www.solarwinds.net/Tools/Free_tools/TFTP_Server/ Vendor was notified of this vulnerability. The vulnerability is not present in the newest version of TFTP Server version 8.2, released in September 2005. 4. Solution Upgrade to TFTP Server version 8.2 or later. 5. Detailed analysis TFTP servers are often used to transfer configuration files and operating system images to routers. TFTP is also used for devices that support PXE booting. Most implementations do trivial filtering on requested filenames such as "../filename" to prevent easy directory traversal. However, it is easy to bypass this filtering by manipulating the filename being requested. With the SolarWinds TFTP server, any file on the system can be downloaded using a request similar to the following: $ tftp 192.168.0.1 tftp> get NUL/....//....//WINNT/win.ini Received 582 bytes in 0.0 seconds tftp> quit $ cat win.ini ; for 16-bit app support [fonts] [extensions] [mci extensions] [files] [Mail] MAPI=1 ... 6. Credit This vulnerability was discovered by Chad Loder of Rapid7. 7. Contact Information Rapid7, LLC Email: advisory (at) rapid7 (dot) com [email concealed] Web: http://www.rapid7.com/ Phone: +1 (617) 247-1717 8. Disclaimer and Copyright Rapid7, LLC. is not responsible for the misuse of the information provided in our security advisories. These advisories are a service to the professional security community. There are NO WARRANTIES with regard to this information. Any application or distribution of this information constitutes acceptance AS IS, at the user's own risk. This information is subject to change without notice. This advisory Copyright (C) 2006 Rapid7, LLC. Permission is hereby granted to redistribute this advisory, providing that no changes are made and that the copyright notices and disclaimers remain intact.