# 123/udp - Pentesting NTP

🎙️ HackTricks LIVE Twitch Wednesdays 5.30pm (UTC) 🎙️ - 🎥 Youtube 🎥

* Do you work in a **cybersecurity company**? Do you want to see your **company advertised in HackTricks**? or do you want to have access to the **latest version of the PEASS or download HackTricks in PDF**? Check the [**SUBSCRIPTION PLANS**](https://github.com/sponsors/carlospolop)! * Discover [**The PEASS Family**](https://opensea.io/collection/the-peass-family), our collection of exclusive [**NFTs**](https://opensea.io/collection/the-peass-family) * Get the [**official PEASS & HackTricks swag**](https://peass.creator-spring.com) * **Join the** [**💬**](https://emojipedia.org/speech-balloon/) [**Discord group**](https://discord.gg/hRep4RUj7f) or the [**telegram group**](https://t.me/peass) or **follow** me on **Twitter** [**🐦**](https://github.com/carlospolop/hacktricks/tree/7af18b62b3bdc423e11444677a6a73d4043511e9/\[https:/emojipedia.org/bird/README.md)[**@carlospolopm**](https://twitter.com/carlospolopm)**.** * **Share your hacking tricks by submitting PRs to the** [**hacktricks repo**](https://github.com/carlospolop/hacktricks) **and** [**hacktricks-cloud repo**](https://github.com/carlospolop/hacktricks-cloud).

Did you know that crypto projects pay more bounty rewards than their web2 counterparts?\ \*\*\*\*This [**crypto bounty alone**](https://hackenproof.com/jungle/jungle-smart-contract) is worth $1.000.000!\ Check out the [**top-paying bounties**](https://hackenproof.com/programs) among crypto projects.\ [**Sign up on HackenProof**](https://hackenproof.com/register?referral_code=i_E6M25i_Um9gB56o-XsIA) to get rewarded without delays and become the web3 hacker legend. {% embed url="" %} ## Basic Information The Network Time Protocol (**NTP**) is a networking protocol for clock synchronization between computer systems over packet-switched, variable-latency data networks. **Default port:** 123/udp ``` PORT STATE SERVICE REASON 123/udp open ntp udp-response ``` ## Enumeration ```bash ntpq -c readlist ntpq -c readvar ntpq -c peers ntpq -c associations ntpdc -c monlist ntpdc -c listpeers ntpdc -c sysinfo ``` ```bash nmap -sU -sV --script "ntp* and (discovery or vuln) and not (dos or brute)" -p 123 ``` ## Examine configuration files * ntp.conf ## NTP Amplification Attack [**How NTP DDoS Attack Works**](https://resources.infosecinstitute.com/network-time-protocol-ntp-threats-countermeasures/#gref) NTP protocol by design uses UDP to operate, which does not require any handshake like TCP, thus no record of the request. So, NTP DDoS amplification attack begins when an attacker crafts packets with a spoofed source IP to make the packets appear to be coming from the intended target and sends them to NTP server. Attacker initially crafts the packet of few bytes, but NTP responds with a large amount of data thus adding to amplification of this attack. *MONLIST command*: It is a NTP protocol command which has very little use, but it is this command which is the main culprit for this attack. However, the use of MONLIST command is to give details of the last 600 clients that have connected to the NTP time service. Below is the command syntax: ```bash ntpdc -n -c monlist ``` ## Shodan * `ntp` ## HackTricks Automatic Commands ``` Protocol_Name: NTP #Protocol Abbreviation if there is one. Port_Number: 123 #Comma separated if there is more than one. Protocol_Description: Network Time Protocol #Protocol Abbreviation Spelled out Entry_1: Name: Notes Description: Notes for NTP Note: | The Network Time Protocol (NTP) is a networking protocol for clock synchronization between computer systems over packet-switched, variable-latency data networks. https://book.hacktricks.xyz/pentesting/pentesting-ntp Entry_2: Name: Nmap Description: Enumerate NTP Command: nmap -sU -sV --script "ntp* and (discovery or vuln) and not (dos or brute)" -p 123 {IP} ```

Did you know that crypto projects pay more bounty rewards than their web2 counterparts?\ This [**crypto bounty alone**](https://hackenproof.com/jungle/jungle-smart-contract) is worth $1.000.000!\ Check out the [**top-paying bounties**](https://hackenproof.com/programs) among crypto projects.\ [**Sign up on HackenProof**](https://hackenproof.com/register?referral_code=i_E6M25i_Um9gB56o-XsIA) to get rewarded without delays and become the web3 hacker legend. {% embed url="" %}

🎙️ HackTricks LIVE Twitch Wednesdays 5.30pm (UTC) 🎙️ - 🎥 Youtube 🎥

--- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://breached.gitbook.io/dashboard/network-services-pentesting/pentesting-ntp.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.