Port 11211 Details
known port assignments and vulnerabilities
3 records found
||Port used by Memcachedb and Apple iCal Server
Memcached is vulnerable to a denial of service, caused by an error when handling TCP packets. By sending a specially-crafted packet containing an overly long string to TCP port 11211, a remote attacker could exploit this vulnerability to cause a segmentation fault and application to crash.
References: [XFDB-83915], [BID-59567]
Memcached version 1.5.5 contains an Insufficient Control of Network Message Volume (Network Amplification, CWE-406) vulnerability in the UDP support of the memcached server that can result in denial of service via network flood (traffic amplification of 1:50,000 has been reported by reliable sources). This attack appear to be exploitable via network connectivity to port 11211 UDP. This vulnerability appears to have been fixed in 1.5.6 due to the disabling of the UDP protocol by default.
References: [CVE-2018-1000115], [EDB-44264], [EDB-44265]
||Memory cache service, registered 2009-02-09
Related ports: 21201
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SANS Internet Storm Center: port 11211
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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