News Glossary of Terms FAQs Polls Cool Links SpeedGuide Teams SG Premium Services SG Gear Store
Registry Tweaks Broadband Tools Downloads/Patches Broadband Hardware SG Ports Database Security Default Passwords User Stories
Broadband Routers Wireless Firewalls / VPNs Software Hardware User Reviews
Broadband Security Editorials General User Articles Quick Reference
Broadband Forums General Discussions
Advertising Awards Link to us Server Statistics Helping SG About
The Broadband Guide
SG
search advanced
 Username:
 Password:
Register
 forgot your password?
Toast.net Performance Testing

Port 81 Details


known port assignments and vulnerabilities
threat/application/port search:
 search
Port(s) Protocol Service Details Source
81 udp trojans W32.Beagle.AR@mm (9.29.2004) - mass mailing worm with backdoor functionality on port 81/tcp & udp. Affects all current Windows versions. SG
81 tcp http Hyper Text Transfer Protocol (HTTP) - ports used for web traffic. See also TCP ports 80, 8080, 8081.

Some common uses for port 81/tcp include web administration (cobalt cube), web proxy servers, etc.

If you're not running web services on this port, keep in mind it is also used by some trojans:
Backdoor.Asylum (05.2000) - remote access trojan, uses ports 81, 2342, 23432 by default.
W32.Beagle.AR@mm (09.29.2004) - port 81.

Stack-based buffer overflow in the RespondeHTTPPendiente function in the HTTP server for SUMUS 0.2.2 allows remote attackers to execute arbitrary code via a large packet sent to TCP port 81.
References: [CVE-2005-1110]

RemoConChubo trojan and Blue Iris also use this port.
SG
81 tcp Torpark - Onion routing (unofficial) Wikipedia
81 tcp trojan Asylum Trojans
81 tcp,udp Unassigned (Removed on 2007-09-06) IANA
81 tcp,udp hosts2-ns HOSTS2 Name Server SANS
81 tcp RemoConChubo [trojan] RemoConChubo SANS
81 tcp,udp hosts2-ns HOSTS2 Name Server Nmap
81 tcp threat W32.Beagle Bekkoame
81 tcp threat Xeory Bekkoame
81 udp threat W32.Beagle Bekkoame
11 records found
jump to:
 go
previous next

Related ports: 80  2342  8080  23432  

« back to SG Ports


External Resources
SANS Internet Storm Center: port 81

Notes:
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.

Please use the "Add Comment" button below to provide additional information or comments about port 81.
  User Reviews/Comments:
    rate:
   avg:
by anonymous - 2013-06-17 05:31
TCP Port 81, used by McAfee Framework Service.
Print this document top