While the accepted answer explains how port 0 is still a real port, it may be helpful to understand how ports work in TCP. Below is a 32-bit-wide diagram of the a TCP packet, to scale. UDP is similar, although a lot simpler (after the ports, it has just a length field and a checksum field before the data).
Mar 29, 2020 · SMB uses either IP port 139 or 445. Port 139: SMB originally ran on top of NetBIOS using port 139. NetBIOS is an older transport layer that allows Windows computers to talk to each other on the same network. Port 445: Later versions of SMB (after Windows 2000) began to use port 445 on top of a TCP stack. Using TCP allows SMB to work over the A vulnerability in TCP port management in Cisco ONS 15454 Series Multiservice Provisioning Platforms could allow an unauthenticated, remote attacker to cause the controller card to unexpectedly reload. More Information: CSCuw26032. Known Affected Releases: 10.51. CVE-2016-9157 Port 445 has already been used by so many other attacks, including the Sasser and Nimda worms, that even if a new worm were to be created, it would probably not change things, according to Russ Jan 16, 2017 · blocking all versions of SMB at the network boundary by blocking TCP port 445 with related protocols on UDP ports 137-138 and TCP port 139, for all boundary devices. US-CERT cautions users and administrators that disabling or blocking SMB may create problems by obstructing access to shared files, data, or devices. Dealing with Port 445 Needless to say, you do NOT want port 445 exposed to the Internet. Like Windows port 135 (which is a whole different problem) port 445 is deeply embedded in Windows and can be difficult or impossible to safely close. While its closure is possible, other dependent services such as DHCP (dynamic host configuration protocol The service uses all the following ports: 135/tcp, 135/udp, 137/udp 138/udp, 139/tcp, 445/tcp. MS Security Bulletin [ MS03-026 ] outlines another critical Buffer Overrun RPC vulnerability that can be exploited via ports 135, 139, 445, 593 (or any other specifically configured RPC port). Oct 29, 2012 · Port 445 (SMB) is one of the most commonly and easily susceptible ports for attacks. Port 445 is a TCP port for Microsoft-DS SMB file sharing. Many (to most) Windows systems, as well as Linux, have this port open by default, with unsecured shares and un-patched systems unknowingly exposed to everyone [that wants to know].
TCP port 445 is used for direct TCP/IP MS Networking access without the need for a NetBIOS layer. This service is only implemented in the more recent verions of Windows (e.g. Windows 2K / XP). The SMB (Server Message Block) protocol is used among other things for file sharing in Windows NT/2K/XP.
Feb 04, 2015 · Opening up SMB ports (TCP 139/TCP 445 among others) to the Internet is such a terrifically bad idea I don't know where to start. Why do you even think you need to do this? I cannot even begin to describe what a thoroughly horrible idea this is. I could not in good conscience assist you in this enterprise. Mar 12, 2020 · For users who are unable to patch immediately, Microsoft’s guidance is to disable SMBv3 compression and block TCP port 445 on firewalls and client computers as a workaround. Rapid7 Analysis. Rapid7 rates this vulnerability as being high value for attackers, but it is not known to be actively exploited in the wild as of time of writing. CVE-2002-0283 : Windows XP with port 445 open allows remote attackers to cause a denial of service (CPU consumption) via a flood of TCP SYN packets containing possibly malformed data. (e.g.: CVE-2009-1234 or 2010-1234 or 20101234) May 19, 2010 · yes i know Hayabusa but why i did it for port 445 only because i know that port 139 netbios not possible to exploit under windows xp sp3 patched system. i tried many times with no success :S. its on sp1 i think only. Understood, but I seem to recall your list also showed port 5101 tcp, as well….
May 15, 2019 · Microsoft introduced TCP port 445 with Windows 2000, and it's still in use in Windows 10 and Windows Server 2019. I'll explain what this port is for, and how it relates to security in Windows. At the same time, I'll also explain how you can disable the old TCP port 139. SMB over TCP vs. SMB over NBT
May 15, 2019 · Microsoft introduced TCP port 445 with Windows 2000, and it's still in use in Windows 10 and Windows Server 2019. I'll explain what this port is for, and how it relates to security in Windows. At the same time, I'll also explain how you can disable the old TCP port 139. SMB over TCP vs. SMB over NBT Mar 03, 2018 · But on Win10, it keeps trying to connect the port 445 and failed. I have tried to choose the "enable NetBIOS over TCP/IP" in the advanced setting page of TCP/IP, but nothing changed. I want to know, is there a way to force Win10 to use port 139 (NetBIOS over TCP/IP) only or disable the directly SMB connection (port 445) to access shared folder? Feb 04, 2015 · Opening up SMB ports (TCP 139/TCP 445 among others) to the Internet is such a terrifically bad idea I don't know where to start. Why do you even think you need to do this? I cannot even begin to describe what a thoroughly horrible idea this is. I could not in good conscience assist you in this enterprise.