EC-Council
312-50V9 · Question #394
312-50V9 Question #394: Real Exam Question with Answer & Explanation
The correct answer is A: OS Scan requires root privileges. Nmap's OS detection feature (-O) requires raw socket access, which is only available to root or administrators, causing the scan to quit when run as an unprivileged user.
Question
Jack was attempting to fingerprint all machines in the network using the following Nmap syntax: invictus@victim_server:~$ nmap -T4 -0 10.10.0.0/24 TCP/IP fingerprinting (for OS scan) xxxxxxx xxxxxx xxxxxxxxx. QUITTING! Obviously, it is not going through. What is the issue here?
Options
- AOS Scan requires root privileges
- BThe nmap syntax is wrong.
- CThe outgoing TCP/IP fingerprinting is blocked by the host firewall
- DThis is a common behavior for a corrupted nmap application
Explanation
Nmap's OS detection feature (-O) requires raw socket access, which is only available to root or administrators, causing the scan to quit when run as an unprivileged user.
Common mistakes.
- B. While the flag shown is '-0' (zero) rather than '-O' (letter O), the error message specifically references TCP/IP fingerprinting failure, pointing to a privileges issue rather than a syntax parse error.
- C. A host firewall blocking outgoing packets would result in no responses or timeouts, not the specific 'TCP/IP fingerprinting QUITTING' error message that indicates an OS-level privilege denial.
- D. A corrupted nmap installation would produce different errors such as missing libraries or segmentation faults, not a consistent privilege-related quit message tied to raw socket creation.
Concept tested. Nmap OS detection root privilege requirement
Reference. https://nmap.org/book/man-os-detection.html
Community Discussion
No community discussion yet for this question.