by Tan Chew Keong
Release Date: 2008-06-27
[en] [jp]
Summary
A vulnerability has been found within the FTP client in AceFTP. When exploited, this vulnerability allows an anonymous attacker to write files to arbitrary locations on a Windows user's system.
Tested Versions
Details
This advisory discloses a vulnerability within the FTP client in AceFTP. When exploited, this vulnerability allows an anonymous attacker to write files to arbitrary locations on a Windows user's system.
The FTP client does not properly sanitise filenames containing directory traversal sequences (forward-slash) that are received from an FTP server in response to the LIST command.
An example of such a response from a malicious FTP server is shown below.
Response to LIST (forward-slash):
-rw-r--r-- 1 ftp ftp 20 Mar 01 05:37 /../../../../../../../../../testfile.txt\r\n
By tricking a user to download a directory from a malicious FTP server that contains files with fowward-slash directory traversal sequences in their filenames, it is possible for the attacker to write files to arbitrary locations on a user's system with privileges of that user. An attacker can potentially leverage this issue to write files into a user's Windows Startup folder and execute arbitrary code when the user logs on.
POC / Test Code
Please download the POC here and follow the instructions below.
Ana Bekuta - — Uspomene - (audio 2008)
Listen to Uspomene by Ana Bekuta on Apple Music. 1999. Duration: 3:45. music.apple.com Ana Bekuta – Uspomene Lyrics - Genius
Ana Bekuta's poignant 1999 ballad, "Uspomene," tells a tale of heartbreak and enduring love. You can find the full lyrics and a translation at the following sites: Genius Musixmatch Ana Bekuta - Uspomene - (Audio 2008)
You can listen to the official audio from the Grand Production archives here: Ana Bekuta - Uspomene - (Audio 2008) Grand Production YouTube• Aug 29, 2012 Uspomene – Song by Ana Bekuta - Apple Music Listen to Uspomene by Ana Bekuta on Apple Music
Patch / Workaround
Avoid downloading files/directories from untrusted FTP servers.
Disclosure Timeline
2008-06-15 - Vulnerability Discovered.
2008-06-16 - Vulnerability Details Sent to Vendor via online support form (no reply).
2008-06-18 - Vulnerability Details Sent to Vendor again via online support form (no reply).
2008-06-25 - Vulnerability Details Sent to Vendor again via online support form (no reply).
2008-06-27 - Public Release.