What is port 139 used for in Windows?
Port 139 is utilized by NetBIOS Session service. Enabling NetBIOS services provide access to shared resources like files and printers not only to your network computers but also to anyone across the internet.
What is the port name for port 139?
| Name: | netbios-ssn |
|---|---|
| Purpose: | NETBIOS Session Service |
| Description: | TCP NetBIOS connections are made over this port, usually with Windows machines but also with any other system running Samba (SMB). These TCP connections form “NetBIOS sessions” to support connection oriented file sharing activities. |
| Related Ports: | 137, 138, 445 |
Why would the network security team be concerned about port 139 being open on a system?
Ports 135-139 range is associated with the SMB and NetBios this indicates that null sessions (no username or password) are allowed. Also, the concern with the ports being open would be when the service is DISabled because if the service is enabled then the ports should be open for the systems to use the service.
Do I need port 139?
If you are on Windows-based network that is running NetBios, it is perfectly normal to have port 139 open in order to facilitate that protocol. If you are not on a network using NetBios, there is no reason to have that port open. E-mail servers need ports 25 and 110 for SMTP and POP, respectively.
Is port 139 still used?
Port 139 is used for File and Printer Sharing but happens to be the single most dangerous Port on the Internet. This is so because it leaves the hard disk of a user exposed to hackers.
Are open ports a security risk?
Open ports can be dangerous when the service listening on the port is misconfigured, unpatched, vulnerable to exploits, or has poor network security rules. The reason people call for closed ports because less open ports reduces your attack surface.
Should I open port 139?
If you are on Windows-based network that is running NetBios, it is perfectly normal to have port 139 open in order to facilitate that protocol. If you are not on a network using NetBios, there is no reason to have that port open.
What is the use of port 135?
Port 135 is used by Messenger Service (not MSN Messenger) and exploited in popup net send messenger spam [MSKB 330904]. To stop the popups you’d need to filter port 135 at the firewall level or stop the messenger service. The service uses all the following ports: 135/tcp, 135/udp, 137/udp 138/udp, 139/tcp, 445/tcp.
What is the difference between port 139 and 445?
Port 139 is used by SMB dialects that communicate over NetBIOS. It’s a transport layer protocol designed to use in Windows operating systems over a network. Port 445 is used by newer versions of SMB (after Windows 2000) on top of a TCP stack, allowing SMB to communicate over the Internet.
Is there a way to exploit port 139?
That being said by Mr Protocol, what he says is true, however, port 139, is usually used to identify Windows systems, so if you’re looking to exploit “port 139” as you put it, first thing you will want to do is identify a system with port 139 open, thoroughly determine if its a true open port, the OS, or if its a honeyport/honeypot.
Is it possible to secure ports 139 and 445?
The good news is that the Windows has since released a security update to Windows XP, Windows Server 2003, Windows 8, Windows Vista, Windows 7, Windows 8.1, Windows 10, Windows Server 2008, Windows Server 2008 R2, Windows Server 2012 and Windows Server 2016 to prevent this exploit. Here are some other ways you can secure port 139 and 445.
Why is port 139 blocked for NetBIOS enumeration?
Conclusion: Although port 139 was blocked but still sharing was possible due to the running protocol on port 445. Hence by blocking port 137 and 139 admin has added a security level that will prevent NetBIOS session service as well as NetBIOS name service for NetBIOS enumeration.
What is port 139 in Windows NT 4.0?
All four ports are open as default in all versions of Windows, including Windows 10 and Windows Server 2019. In the case of Windows NT 4.0, null sessions always used port 139. A tool like Winfo can give you much information on Windows NT 4.0, but how does this work on Windows 2000 and newer versions?