Port 4840 Details
known port assignments and vulnerabilities
3 records found
||Unspecified vulnerability in the server in Certec EDV atvise before 2.1 allows remote attackers to cause a denial of service (daemon crash) via crafted requests to TCP port 4840.
References: [CVE-2011-4873], [BID-51553]
An XXE vulnerability has been identified in OPC Foundation UA .NET Sample Code before 2017-03-21 and Local Discovery Server (LDS) before 1.03.367. Among the affected products are Siemens SIMATIC PCS7 (All versions V8.1 and earlier), SIMATIC WinCC (All versions < V7.4 SP1), SIMATIC WinCC Runtime Professional (All versions < V14 SP1), SIMATIC NET PC Software, and SIMATIC IT Production Suite. By sending specially crafted packets to the OPC Discovery Server at port 4840/tcp, an attacker might cause the system to access various resources chosen by the attacker.
References: [CVE-2017-12069], [BID-100559]
||OPC UA Connection Protocol, modified: 2018-01-04
||OPC UA Multicast Datagram Protocol, registered 2006-09, modified: 2018-01-04
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SANS Internet Storm Center: port 4840
Well Known Ports: 0 through 1023.
Registered Ports: 1024 through 49151.
Dynamic/Private : 49152 through 65535.
TCP ports use the Transmission Control Protocol. TCP is the most commonly used protocol
on the Internet and any TCP/IP network. Whereas the IP protocol deals only with packets, TCP enables two hosts
to establish a connection and exchange streams of data. TCP guarantees delivery of data
and that packets will be delivered in the same order in which they were sent.
Guaranteed communication/delivery is the key difference between TCP and UDP.
UDP ports use the Datagram Protocol, a communications protocol for the Internet network,
transport, and session layers. Like TCP (Transmission Control Protocol),
UDP is used with IP (the Internet Protocol) and makes possible the transmission of datagrams
from one computer to applications on another computer, but unlike TCP, UDP is connectionless
and does not guarantee reliable communication; it's up to the application that received
the message to process any errors and verify correct delivery. UDP is often used with time-sensitive
applications, such as audio/video streaming, where dropping some packets is preferable to waiting for delayed data.
When troubleshooting unknown open ports, it is useful to find exactly what services/processes are listening to them.
This can be accomplished in both Windows command prompt and Linux variants using the "netstat -aon" command.
We also recommend runnig multiple anti-virus/anti-malware scans to rule out the possibility of active malicious software.
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