ColoradoFTP 1.3 Prime Edition (Build 8) Directory Traversal
Posted on 13 August 2016
################################################### 01. ### Advisory Information ### Title: Directory Traversal Vulnerability in ColoradoFTP v1.3 Prime Edition (Build 8) Date published: n/a Date of last update: n/a Vendors contacted: ColoradoFTP author Sergei Abramov Discovered by: Rv3Laboratory [Research Team] Severity: High 02. ### Vulnerability Information ### OVE-ID: OVE-20160718-0006 CVSS v2 Base Score: 8.5 CVSS v2 Vector: (AV:N/AC:M/Au:S/C:C/I:C/A:C) Component/s: ColoradoFTP Core v1.3 Class: Path Traversal 03. ### Introduction ### ColoradoFTP is the open source Java FTP server. It is fast, reliable and extendable. Fully compatible with RFC 959 and RFC 3659 (File Transfer Protocol and Extensions) this implementation makes it easy to extend the functionality with virtually any feature. Well commented source code and existing plug-ins make it possible to shape the FTP server just the way you want! http://cftp.coldcore.com/ 04. ### Vulnerability Description ### The default installation and configuration of Colorado FTP Prime Edition (Build 8) is prone to a security vulnerability. Colorado FTP contains a flaw that may allow a remote attacker to traverse directories on the FTP server. A remote attacker (a colorado FTP user) can send a command (MKDIR, PUT, GET or DEL) followed by sequences (\..\) to traverse directories and create, upload, download or delete the contents of arbitrary files and directories on the FTP server. To exploit the vulnerability It is important to use "\" at the beginning of string. 05. ### Technical Description / Proof of Concept Code ### By supplying "\..\..\..\..\" in the file path, it is possible to trigger a directory traversal flaw, allowing the attacker (anonymous user or Colorado FTP user) to upload or download a file outside the virtual directory. 05.01 We tried to upload a file (netcat - nc.exe), to Windows %systemroot% directory (C:WINDOWSsystem32) using a PUT command: ftp> put nc.exe \..\..\..\Windows\system32\nc.exe Netcat was successfully uploaded. 05.02 We tried to create a directory (test), using a MKDIR command: ftp> mkdir nc.exe \..\..\..\test The directory test was successfully created. 06. ### Business Impact ### This may allow an attacker to upload and download files from remote machine. 07. ### Systems Affected ### This vulnerability was tested against: ColoradoFTP v1.3 Prime Edition (Build 8) O.S.: Microsoft Windows 7 32bit JDK: v1.7.0_79 Others versions are probably affected too, but they were not checked. 08. ### Vendor Information, Solutions and Workarounds ### This issue is fixed in ColoradoFTP Prime Edition (Build 9), which can be downloaded from: http://cftp.coldcore.com/download.htm 09. ### Credits ### Rv3Laboratory [Research Team] - www.Rv3Lab.org This vulnerability has been discovered by: Rv3Lab - [www.rv3lab.org] - research(at)rv3lab(dot)org Christian Catalano aka wastasy - wastasy(at)rv3lab(dot)org Marco Fornaro aka Chaplin89 - chaplin89(at)rv3lab(dot)org 10. ### Vulnerability History ### July 07th, 2016: Vulnerability discovered. July 19th, 2016: Vendor informed. [Colorado FTP team] July 21st, 2016: Vendor responds asking for details. July 28th, 2016: Sent detailed information to the vendor. August 08th, 2016: Vendor confirms vulnerability. August 10th, 2016: Vendor reveals patch release date. August 11th, 2016: Vulnerability disclosure 11. ### Disclaimer ### The information contained within this advisory is supplied "as-is" with no warranties or guarantees of fitness of use or otherwise. We accept no responsibility for any damage caused by the use or misuse of this information. 12. ### About Rv3Lab ### Rv3Lab is an independent Security Research Lab. For more information, please visit [www.Rv3Lab.org] For more information regarding the vulnerability feel free to contact the Rv3Research Team: research(at)rv3lab(dot)org ###################################################
