Port 123 (tcp/udp) :: SpeedGuide

2024-12-28 Port 123Details known port assignments and vulnerabilities threat/application/port search: Port(s) Protocol service Details So

Port 123Details

known port assignments and vulnerabilities

threat/application/port search:

Port(s)	Protocol	service	Details	Source
123	udp	NTP	Network Time Protocol (NTP) – used for time synchronization [RFC 5905] Security Concerns: It provides both information and possible avenue of attack for intruders. Info gathered can include system uptime, time since reset, time server pkt, I/O & memory statistics and ntp peer list. If a host is susceptible to time altering via ntp an attacker can possibly: 1 ) run replay attack using capture OTP and kerberos ticket before they expire . 2 ) stop security – relate cron job from run or cause them to run at incorrect time . 3) Make system and audit logs unreliable since time is alterable. Vodafone Sure Signal also uses this port	SG
123	tcp	trojan	Net Controller trojan Network Time Protocol (NTP), as specified in RFC 5905, uses port 123even for modes where a fixed port number is not required, which makes it easier for remote attackers to conduct off-path attacks. References: [CVE-2019-11331], [BID-108010], [XFDB-159889]	SG
123	udp		Network Time Protocol (NTP) – used for time synchronization (official)	Wikipedia
123	tcp	trojan	[ trojan ] Net Controller	Trojans
123	tcp	NetController	[ trojan ] Net Controller	SANS
123	tcp , udp	applications	NTP	Portforward
123	tcp	threat	Madfind	Bekkoame
123	tcp , udp	ntp	Network Time Protocol [RFC5905]	IANA

8 records is found find

Related ports: 50 500 4500 33434

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External Resources

SANS ISC: port 123

Notes:

Port numbers in computer networking represent communication endpoints. Ports are unsigned 16-bit integers (0-65535) that identify
a specific process, or network service. IANA is responsible for internet protocol resources, including the registration of commonly
used port numbers for well-known internet services.

Well know Ports : 0 through 1023 .

register Ports : 1024 through 49151 .

Dynamic/Private : 49152 through 65535.

TCP ports is use use the Transmission Control Protocol , the most commonly used protocol
on the internet and any TCP / IP network . TCP is enables enable two host
to establish a connection and exchange stream of datum . TCP guarantee delivery of datum
and that packet will be deliver in the same order in which they were send .
guarantee communication / delivery is is is the key difference between TCP and UDP .

UDP ports use the Datagram Protocol. Like TCP, UDP is used in combination with IP (the Internet Protocol)
and facilitates 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 and realtime gaming, where dropping some packets is preferable to waiting for delayed data.

When troubleshoot unknown open port , it is is is useful to find exactly what service / process are listen to them .
This can be accomplish in both Windows command prompt and Linux variant using the ” netstat -aon ” command .
We is recommend also recommend runnig multiple anti – virus / anti – malware scan to rule out the possibility of active malicious software .
For more detailed and personalized help please use our forum .

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