NMAP, or Network Mapper, is a free and open-source tool used for network discovery, administration, and security auditing. While it’s primarily utilized for network mapping and port scanning, NMAP can also serve as a powerful vulnerability scanner when used in combination with some scripts.
NMAP uses a process called the NMAP Scripting Engine (NSE) to run scripts that can perform a wide range of networking tasks, including vulnerability scanning. These scripts use a LUA programming language and can perform tasks that extend NMAP’s native capabilities.
To run a vulnerability scan with NMAP, you’ll need to use the following command: “nmap -sV —script=vuln target” where “target” is the IP address or hostname you wish to scan.
The -sV option tells NMAP to determine the version of any services running on the ports. The –script=vuln is an argument that instructs NMAP to load scripts that are categorized as vulnerability scripts from its database. You can specify specific scripts using the —script option followed by the name of the script (Wortmann, 2021).
NMAP has a plethora of scripts ranging from HTTP to SSH and SMB vulnerabilities. For example, the http-vuln-cve2014-2126.nse script can check if a target machine is vulnerable to the specified CVE. This script looks for a flaw in OpenSSL that allows an attacker to reveal up to 64kB of memory to a connected client or server (NMAP, n.d.).
Another NMAP script example for vulnerability scanning is smb-vuln-ms08-067 which checks windows systems for vulnerability MS08-067, allowing remote code execution if an affected system received a specially crafted RPC request (NMAP, n.d.).
Before you conduct vulnerability scanning, remember that scanning someone’s network without their permission is illegal. Always ensure you have explicit consent before conducting any scans.
In conclusion, NMAP is a handy tool for vulnerability scanning and as with any tool in this sphere, it comes with a level of responsibility. Additionally, due to NMAP running scripts from its database, it is vital to regularly update it to preserve its effectiveness in scanning for the latest vulnerabilities.
Sources:
- NMAP. (n.d.). NMAP Scripting Engine Documentation. Retrieved from https://nmap.org/book/nse.html
- Wortmann, N. (2021). Network Scanning: The Most Important Techniques Explained. Retrieved from https://www.paessler.com/it-explained/network-scanning
