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
Â
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.
Download Cupd Tnk Zip 🎉
When you find a download link for a file like "CUPD TNK.zip," follow these standard security and technical steps: Instructions for Downloading ZIP Files
: It uses mathematical algorithms to reduce the total file size, saving storage space and speeding up transfer times. How to Download and Extract Safely Download CUPD TNK zip
However, since you are looking to download and manage a file, here is a deep dive into how to securely download such files and why they are used. Understanding the ZIP File Format When you find a download link for a file like "CUPD TNK
There are no official software packages or mainstream tools currently identified under the specific name "CUPD TNK." This term appears to be a highly specific or localized file name, possibly related to a particular project, educational resource, or niche industry. : It bundles multiple files or folders into
: It bundles multiple files or folders into a single container for easier sharing.
A .ZIP file is a . It serves two primary functions:
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.