Remote Framebuffer
RFB (Remote Framebuffer) protocol on port 5900 is primarily used by VNC (Virtual Network Computing) services to provide remote access to graphical user interfaces. This protocol enables users to control a remote computer as if they were sitting in front of it. It is widely used for remote technical support and administration.
What is Remote Framebuffer
RFB (Remote Framebuffer) protocol, operating on port 5900, is a network protocol that allows remote access to graphical user interfaces. It is most commonly associated with VNC (Virtual Network Computing) services, which enable users to control a remote computer's desktop environment. This capability is particularly useful for remote technical support, system administration, and accessing applications from different locations.
The RFB protocol was originally developed by the Olivetti & Oracle Research Lab in the late 1990s. It has since become an open standard, with numerous implementations available, both free and commercial. The protocol works by transmitting the framebuffer (the graphical output) from the server to the client, while user inputs (keyboard and mouse events) are sent back to the server.
One of the key advantages of RFB is its simplicity and flexibility. It can be used across different operating systems and platforms, making it a versatile tool for various remote access needs. However, because it transmits graphical data, it can be bandwidth-intensive, especially over slower network connections.
Despite its utility, using RFB over port 5900 comes with security risks. The protocol itself does not include strong encryption, making it vulnerable to interception and unauthorized access if not properly secured. It is recommended to use additional security measures, such as tunneling RFB traffic through SSH or using VPNs, to protect the data being transmitted.
Remote Framebuffer runs on TCP and UDP port 5900 and is official IANA port.Security risk
If port 5900 is open and the RFB service is running, it can expose the system to unauthorized access and potential data breaches. The protocol lacks strong encryption, making it susceptible to interception. To mitigate these risks, it is crucial to implement additional security measures such as SSH tunneling or VPNs.
In our UFW tutorial you can follow instructions how you can configure UFW to close port 5900. Use StackChanges to monitor if the Remote Framebuffer port is closed and stays closed. StackChanges will send an alert if port 5900 is open again.