| vuln.sg Vulnerability Research Advisory |
by Tan Chew Keong 
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. Download - Hdmovies4u.tv-la.la.land.2016.1080p... -As he waited for the download to complete, John couldn't shake off the feeling that he had made a mistake. He had heard about the dangers of downloading pirated content, but he had been tempted by the promise of a free movie. However, as the download progressed, John's computer started to behave strangely. It began to slow down, and he noticed that other programs were becoming unresponsive. He tried to close the download manager, but it wouldn't budge. Suddenly, a pop-up message appeared on his screen, warning him about potential malware threats. Download - HDMovies4u.Tv-La.La.Land.2016.1080p... When the download finally finished, John hesitated to open the file. He wasn't sure if it was safe, and he didn't want to compromise his computer's security. But his curiosity got the better of him, and he decided to watch the movie. As he waited for the download to complete,
Avoid downloading files/directories from untrusted FTP servers.
Disclosure Timeline
2008-06-15 - Vulnerability Discovered. |
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