Writeups

InfoSec Prepration

Link : https://www.vulnhub.com/entry/infosec-prep-oscp,508/

Difficulty level: easy

Summary:

The basic enumeration is associated with checking the sub-dirs and commons like robots.txt. A taste of escalating privileges with misconfigured suid binary of bash is present.

Enumeration:

Nmap scan:

Started with an aggressive TCP Nmap scan

Found /secret.txt from /robots.txt and the following key from there:

LS0tLS1CRUdJTiBPUEVOU1NIIFBSSVZBVEUgS0VZLS0tLS0KYjNCbGJuTnphQzFyWlhrdGRqRUFB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\nT1BFTlNTSCBQUklWQVRFIEtFWS0tLS0tCg==\n

which is the base64 encoded format of the OpenSSH private key, file here

Finally,

From the website got the user i.e. oscp. Got into the server using the keys and user above.

Got the first flag from the same folder.

Privilege Escalation:

Found the database user and password from /var/www/html/wp-config.php which is as follows:

define( 'DB_NAME', 'wordpress' );
define( 'DB_USER', 'wordpress' );
define( 'DB_PASSWORD', 'Oscp12345!' );
define( 'DB_HOST', 'localhost' );
$debian_server = preg_replace('/:.*/', "", $_SERVER['HTTP_HOST']);
if (!defined('DB_NAME'))
    define('DB_NAME', 'wordpress');
if (!defined('DB_USER'))
    define('DB_USER', 'wordpress');
if (!defined('DB_HOST'))
    define('DB_HOST', 'localhost');

Got the user admin and noithing more from the database.

Tried everything but could not get more into it so used Linpeas.sh to further get into the server but failed.

Finally tried to get the suid bits which had the root privileges using find / -perm /4000 2>/dev/null and got /usr/bin/bash which looked suspicious. Got to GTFOBins to look into it and found the expoit to it.

Finally got the root privileges and pwnned the machine successfully.