| 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. Quarkxpress 70 Portable Better ((better))Since Quark never released an official portable version, these builds are typically "repacked" by third-party groups. They use virtualization tools (like Thinstall or VMware ThinApp) to encapsulate the application into a single executable. When you run it, the software "tricks" Windows into thinking the Registry entries exist temporarily in a sandbox. In this article, we will dissect the promise of QuarkXPress 7.0 Portable, compare it to standard installations and modern competitors, and answer the ultimate question: quarkxpress 70 portable better It leaves no registry footprint on host computers. Since Quark never released an official portable version,
Avoid downloading files/directories from untrusted FTP servers.
Disclosure Timeline
2008-06-15 - Vulnerability Discovered. |
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