pptp

PPTP (Point-to-Point Tunneling Protocol) is a method for implementing virtual private networks. It encapsulates PPP packets into IP datagrams for transmission over the Internet or other public networks. PPTP is known for its ease of setup and compatibility with various operating systems.

What is pptp

PPTP (Point-to-Point Tunneling Protocol) is a network protocol that enables the secure transfer of data from a remote client to a private server by creating a virtual private network (VPN). Developed by a consortium led by Microsoft, PPTP encapsulates PPP (Point-to-Point Protocol) frames in IP datagrams for transmission over the Internet or other public IP networks.

PPTP is widely used due to its simplicity and ease of setup. It is supported by many operating systems, including Windows, Linux, and macOS, making it a versatile choice for establishing VPN connections. The protocol uses TCP port 1723 for control messages and GRE (Generic Routing Encapsulation) for encapsulating PPP frames.

Despite its popularity, PPTP has known security vulnerabilities. It relies on the MS-CHAP-v1/v2 authentication protocols, which have been shown to be susceptible to brute-force attacks. As a result, many organizations have moved to more secure VPN protocols like L2TP/IPsec or OpenVPN. However, PPTP remains in use for applications where ease of setup and compatibility are prioritized over security.

pptp runs on TCP and UDP port 1723 and is official IANA port.

Security risk

If port 1723 is open and PPTP is running, the service may be vulnerable to various security threats, including brute-force attacks on the MS-CHAP-v1/v2 authentication protocols. This could potentially allow unauthorized access to the network, leading to data breaches and other security incidents. It is advisable to use more secure VPN protocols if possible.

In our UFW tutorial you can follow instructions how you can configure UFW to close port 1723. Use StackChanges to monitor if the pptp port is closed and stays closed. StackChanges will send an alert if port 1723 is open again.