Vulnerability Details

Nmap NSE net: dhcp-discover

Published: 2011-06-01 14:32:46

CVSS Base Vector:

Detection Type:

Sends a DHCPDISCOVER request to a host on UDP port 67. The response comes back to UDP port 68, and is read using pcap (due to the inability for a script to choose its source port at the moment). DHCPDISCOVER is a DHCP request that returns useful information from a DHCP server. The request sends a list of which fields it wants to know (a handful by default, every field if verbosity is turned on), and the server responds with the fields that were requested. It should be noted that the server doesn't have to return every field, nor does it have to return them in the same order, or honour the request at all. A Linksys WRT54g, for example, completely ignores the list of requested fields and returns a few standard ones. This script displays every field it receives. With script arguments, the type of DHCP request can be changed, which can lead to interesting results. Additionally, the MAC address can be randomized, which should override the cache on the DHCP server and assign a new IP address. Extra requests can also be sent to exhaust the IP address range more quickly. DHCPINFORM is another type of DHCP request that requests the same information, but doesn't reserve an address. Unfortunately, because many home routers simply ignore DHCPINFORM requests, we opted to use DHCPDISCOVER instead. Some of the more useful fields: * DHCP Server (the address of the server that responded) * Subnet Mask * Router * DNS Servers * Hostname SYNTAX: fake_requests: Set to an integer to make that many fake requests before the real one(s). This could be useful, for example, if you also use 'randomize_mac' and you want to try exhausting all addresses. requests: Set to an integer to make up to that many requests (and display the results). randomize_mac: Set to 'true' or '1' to send a random MAC address with the request (keep in mind that you may not see the response). This should cause the router to reserve a new IP address each time. dhcptype: The type of DHCP request to make. By default, DHCPDISCOVER is sent, but this argument can change it to DHCPOFFER, DHCPREQUEST, DHCPDECLINE, DHCPACK, DHCPNAK, DHCPRELEASE or DHCPINFORM. Not all types will evoke a response from all servers, and many require different fields to contain specific values.

Detection Plugin
CVSS Score
Nmap NSE net

Free Vulnerability Scanning, Assessment and Management

Mageni's Platform is packed with all the features you need to scan, assess and manage vulnerabilities like this - it is free, open source, lightning fast, reliable and scalable.


Frequently Asked Questions

No, you can scan concurrently as many assets as you want. Please note that you must be aware of the hardware requeriments of the platform to ensure a good performance.

No, you can add as many assest as you want. It doesn't matters if you have millions of assets, we won't charge you for that.

No. The software is completely free. We have no intention to charge you to use the software, in fact - it completely goes against our beliefs and business model.

A vulnerability is defined in the ISO 27002 standard as “A weakness of an asset or group of assets that can be exploited by one or more threats” (International Organization for Standardization, 2005)

We generate revenue by providing support and other services for customers that require a subscription so they get guaranteed support and enterprise services. To use Mageni's Platform is completely free, with no limits at all.

Yes. Mageni understands that there are professionals and businesses that need commercial support so Mageni provides an active support subscription with everything needed to run Mageni's Platform reliably and securely. More than software, it's access to security experts, knowledge resources, security updates, and support tools you can't get anywhere else. The subscription includes:

  • Ongoing delivery
    • Patches
    • Bug fixes
    • Updates
    • Upgrades
  • Technical support
    • 24/7 availability
    • Unlimited Incidents
    • Specialty-based routing
    • Multi-Channel
  • Commitments
    • Software certifications
    • Software assurance
    • SLA

No, we don't store the information of your vulnerabilities in our servers.

Vulnerability management is the process in which vulnerabilities in IT are identified and the risks of these vulnerabilities are evaluated. This evaluation leads to correcting the vulnerabilities and removing the risk or a formal risk acceptance by the management of an organization. The term vulnerability management is often confused with vulnerability scanning. Despite the fact both are related, there is an important difference between the two. Vulnerability scanning consists of using a computer program to identify vulnerabilities in networks, computer infrastructure or applications. Vulnerability management is the process surrounding vulnerability scanning, also taking into account other aspects such as risk acceptance, remediation etc. Source: "Implementing a Vulnerability Management Process". SANS Institute.

I am ready to start scanning for vulnerabilities