Understanding and Securing Port 135: Benefits, Risks, and Best Practices

Port 135, also known as the Remote Procedure Call (RPC) Endpoint Mapper, is a network port that is commonly used by the Microsoft Windows operating system for communication between computers on a network. In this article, we will discuss how this port works, its advantages and disadvantages, and how to secure it.

How Does Port 135 Work?

Port 135 is used to map RPC services to the ports they are using on a particular computer. RPC is a protocol that allows a program running on one computer to call a subroutine on another computer without the programmer needing to know the network details of that computer. When a program wants to call a subroutine on a remote computer, it sends a message to the RPC Endpoint Mapper on that computer, specifying the name of the RPC service it wants to call. The RPC Endpoint Mapper then returns the port number that the service is using, which the program can use to communicate with the service.

Advantages of Port 135

Port 135 has several advantages, including:

1. Efficient Communication: RPC allows for efficient communication between computers on a network, making it ideal for large-scale systems.

2. Automation: RPC can automate tasks that would otherwise require manual intervention, reducing the workload of IT administrators.

3. Cross-Platform Support: RPC can be used on different operating systems, making it ideal for heterogeneous networks.

Disadvantages of Port 135

Port 135 also has some disadvantages, including:

1. Security Risks: Port 135 is a well-known port and is often targeted by hackers for attacks such as Distributed Denial of Service (DDoS), which can cause significant downtime and loss of data.

2. Vulnerability to Exploits: Port 135 is vulnerable to exploits such as buffer overflow attacks, which can allow attackers to gain unauthorized access to a computer system.

3. Lack of Encryption: RPC traffic is not encrypted by default, making it vulnerable to interception and eavesdropping.

Securing Port 135

To secure port 135, you can take the following steps:

1. Disable unnecessary RPC services: Disable any RPC services that are not needed on a particular computer or network.

2. Firewall rules: Implement firewall rules to restrict access to port 135. This can prevent unauthorized access and reduce the risk of attacks.

3. Use Encryption: Use encryption to secure RPC traffic. This can be done by configuring RPC to use Transport Layer Security (TLS) or Secure Sockets Layer (SSL) protocols.

4. Regular updates: Ensure that your operating system and software are updated regularly to protect against known vulnerabilities and exploits.

Summary

Port 135 is a network port used by the Microsoft Windows operating system for communication between computers on a network. It allows for efficient communication, automation, and cross-platform support. However, it is also vulnerable to security risks, exploits, and lacks encryption. To secure port 135, you should disable unnecessary RPC services, implement firewall rules, use encryption, and regularly update your operating system and software.