3690 - Pentesting Subversion (svn server)

👉 Overview

👀 What ?

Subversion, also known as SVN, is an open-source version control system that is widely used to manage and track changes to files and directories. Pentesting Subversion refers to the process of conducting penetration testing on an SVN server to identify vulnerabilities that could be exploited by a malicious actor.

🧐 Why ?

Pentesting Subversion is crucial as it helps to identify weaknesses in the SVN server that could allow unauthorized access to sensitive information or even enable a complete takeover of the system. Understanding these vulnerabilities allows organizations to take proactive steps to secure their SVN servers, reducing the risk of data breaches and other cyber threats.

⛏️ How ?

Pentesting Subversion can be done using a variety of tools and techniques. Some common steps include scanning the SVN server for open ports, testing for vulnerabilities such as weak passwords or outdated software versions, and attempting to exploit these vulnerabilities to gain unauthorized access or escalate privileges. It is important to conduct these tests in a controlled environment and to have permission from the system owner to avoid legal issues.

⏳ When ?

Pentesting should be conducted regularly, ideally as part of a routine security audit. This ensures that any new vulnerabilities are identified and addressed promptly. It is also recommended to carry out additional tests after any major changes to the SVN server, such as software updates or modifications to the server configuration.

⚙️ Technical Explanations

Pentesting an SVN server is a comprehensive process that involves multiple steps. The first step is to scan the server's TCP port, usually port 3690, which is the default port that SVN uses for network communication. This can be done using network scanning tools such as nmap. Network scans help to identify open ports and detect the version of SVN running on the server, which can provide useful information about potential vulnerabilities.

Once the open ports and SVN version have been identified, the next step in the pentesting process is to test for known vulnerabilities. This could be done in several ways. One method is to conduct brute-force attacks to identify weak passwords. Brute force attacks involve systematically guessing passwords until the correct one is found. These attacks can be time-consuming but can be highly effective against weak passwords.

Another method for identifying vulnerabilities is to exploit known weaknesses in the SVN software. This requires a comprehensive understanding of the specific SVN version running on the server and any associated vulnerabilities. If a vulnerability is found, it can potentially be exploited to gain unauthorized access or escalate privileges on the server.

If a vulnerability is successfully exploited, the pentester can then attempt to escalate privileges or access sensitive data on the server. This could provide the pentester with valuable information about the server's security posture and any additional vulnerabilities that may exist.

Finally, once the pentest has been completed, all findings should be thoroughly documented and reported to the system owner. This should include a detailed explanation of the vulnerabilities identified, the methods used to exploit them, and the potential impact of these vulnerabilities. The report should also include recommendations for mitigating the identified vulnerabilities and improving the overall security of the SVN server. This could involve steps such as updating the SVN software to the latest version, strengthening password policies, or implementing additional security measures such as firewalls or intrusion detection systems.

For example, to start the penetration testing process, you might initially run an nmap scan on the target SVN server to identify open ports and the SVN version. Your command might look similar to the following:

nmap -p 3690 -sV target_ip

In this command, -p 3690 specifies the port number you're scanning (SVN's default port), -sV enables version detection, and target_ip is the IP address of your target SVN server.

The output might give you something like:

PORT     STATE SERVICE VERSION
3690/tcp open  svnserve Subversion

This indicates that the SVN server is running on port 3690 and is open for network communication.

Next, you might want to conduct a brute-force attack to identify weak passwords. For this, you could use a tool like hydra. An example command might be:

hydra -l user -P passlist.txt target_ip svn

Here, -l user specifies the username you're trying to crack, -P passlist.txt specifies the file containing the list of passwords you're using for the attack, target_ip is the IP address of the target SVN server, and svn is the service you're attacking.

If a vulnerability is found, like a weak password, you could potentially exploit it to gain unauthorized access. For example, with the correct password, you could use svn checkout to download sensitive data:

svn checkout svn://target_ip/repo --username user --password pass

Finally, once you've completed the pentest, you should document your findings, detailing the vulnerabilities identified, the methods used to exploit them, and potential impact. For example: "The SVN server had a weak password 'password1' for the user 'admin'. This allowed unauthorized access to the server, potentially exposing sensitive code or data. It's recommended to update the password policy, enforcing strong, complex passwords."

Remember: This is just an example and should only be carried out in a controlled environment and with permission.