Directory Traversal in SmartFTP

[advisory () htbridge ch]

Vulnerability ID: HTB22525
Reference: http://www.htbridge.ch/advisory/directory_traversal_in_smartftp.html
Product: SmartFTP
Vendor: SmartSoft Ltd ( http://www.smartftp.com/ ) 
Vulnerable Version: 4.0.1124.0 (32 and 64 bit) and Probably Prior Versions
Vendor Notification: 22 July 2010 
Vulnerability Type: Directory Traversal Vulnerability
Status: Fixed by Vendor
Risk level: High 
Credit: High-Tech Bridge SA - Ethical Hacking & Penetration Testing (http://www.htbridge.ch/) 

Vulnerability Details:
When exploited, this vulnerability allows an anonymous attacker to write files to specified locations on a user's 
system.

The FTP client does not properly sanitise filenames containing directory traversal sequences that are received from an 
FTP server, for example
file named as "..\..\..\..\..\..\..\somefile.exe".

By tricking a user to download a directory from a malicious FTP server that contains files with backslash directory 
traversal sequences in their filenames, 
an attacker can potentially write files into a user's Startup folder to execute malicious code when the user logs on.

Solution: Upgrade to the most recent version