ECCouncil CEH v13 312-50v13 Question # 163 Topic 17 Discussion

This question is about web link enumeration using Linux CLI tools — a common initial step during information gathering in penetration testing, covered in CEH v13 Module 02: Footprinting and Reconnaissance.

Objective:

Extract all hyperlinks (i.e., ) from the homepage of a target site to collect subpages, links, or external URLs.

Let’s analyze each component of Option B:

=

=

curl -s <a href="https://site.com">https://site.com | grep '

curl -s <a href="https://site.com:">https://site.com: Silently fetches the HTML source of the main page.

grep '

grep "site.com": Further filters those that point to site.com.

cut -d "v" -f 2: Cuts the line based on the delimiter v to isolate part of the URL — though not perfect, it attempts to extract the visible link.

While not perfectly formed (due to slightly inconsistent quote usage), Option B demonstrates the correct logic chain for web link enumeration using pipes in Linux: fetching, filtering, and extracting.

Why Other Options Are Incorrect:

A. dirb <a href="https://site.com">https://site.com | grep "site"

❌ dirb is used for brute-forcing directories, not grabbing links from HTML.

C. wget https://site.com | grep "

❌ Incorrect. wget will download the entire content (including binary files by default), and piping it directly to grep without -O - or -q -O - makes it ineffective.

D. wget <a href="https://site.com">https://site.com | cut -d "http"

❌ Incorrect. Syntax error (cut -d"http" is invalid without correct delimiter formatting), and again wget needs to be directed to stdout using -O -.

Corrected Optimal Syntax for Real-World Use:

bash

CopyEdit

curl -s https://site.com | grep -oP 'href="\Khttp[^"]+' | grep "site.com"

This uses -oP with Perl-compatible regex to extract only URLs and is a method recommended in CEH iLabs and demonstrations.

Reference from CEH v13 Study Materials:

Module 02 – Footprinting and Reconnaissance, Section: Website Footprinting and Web Crawling

CEH iLabs – Website Information Gathering Lab

CEH Engage Range: Passive and Active Footprinting Phase – Linux Scripting Tasks