mcpbeat

Hunt Clickjacking

elementalsouls/hunt-clickjacking

Hunt Clickjacking — missing X-Frame-Options / CSP frame-ancestors lets an attacker embed the target page in an invisible iframe and trick victims into clicking buttons they cannot see (UI redressing). Targets: login flows, money transfers, account settings, OAuth confirmation pages. Confirm by fetching the page, then PROVE it frames in a real browser and a sensitive state-changing action survives the cross-site context (SameSite cookies / framebusting JS can defeat it) — header-absence alone is not a finding.

1k tokens
context cost
the whole folder, loaded on every use
1
files
instructions only
0
copies elsewhere
how many repositories repackaged it
3280
stars on the repo
on the repository, not the skill itself

Install

one command, takes just this skill from the repository 
npx skills add https://github.com/elementalsouls/Claude-BugHunter --skill hunt-clickjacking

The instruction itself

5 sections, as written by the author

What is Clickjacking

Clickjacking (UI Redressing) lets an attacker load a target page inside a transparent iframe on a malicious site. The victim sees the attacker's decoy UI but clicks the hidden target UI beneath it. No JavaScript on the target is required.

Highest-value targets:

  • Login / authentication pages — force login with attacker credentials
  • Money transfer / checkout / "confirm payment" buttons
  • Account settings (email change, password change, 2FA disable)
  • OAuth / social-login "Authorize app" confirmation dialogs
  • Admin actions (delete, promote user, change role)

Protection Headers

Two mechanisms prevent framing:

X-Frame-Options: DENY              # strongest — blocks all framing
X-Frame-Options: SAMEORIGIN        # allows same-origin frames only
Content-Security-Policy: frame-ancestors 'none'     # CSP equivalent of DENY
Content-Security-Policy: frame-ancestors 'self'     # CSP equivalent of SAMEORIGIN

If NEITHER is present, the page is frameable from any origin.

How to Test

Header-absence is the trigger for investigation, not the finding. Two steps:

Step 1 — Header check (screening). Fetch the target page and inspect the response headers:

curl -sI https://target.example/account/transfer | grep -iE 'x-frame-options|content-security-policy'

If BOTH X-Frame-Options and CSP frame-ancestors are absent, the page is a *candidate*. If either is present and restrictive (DENY/SAMEORIGIN/frame-ancestors 'none'|'self'), stop — it's protected.

Step 2 — Prove it actually frames and clicks (required for a real finding). Build a minimal PoC and load it in a real browser:

<!doctype html>
<h1>Win a prize — click below</h1>
<iframe src="https://target.example/account/transfer"
        style="opacity:0.1;position:absolute;top:0;left:0;width:1000px;height:800px"></iframe>

Confirm ALL of the following, or it is not exploitable:

  • The page actually renders inside the iframe (no framebusting JS that blanks/redirects it — e.g. if(top!==self) breakout, or a Sec-Fetch-Dest/JS frame check).
  • The sensitive action still works while framed — critically, the action must succeed *cross-site*. If it relies on a session cookie set SameSite=Lax or SameSite=Strict (the modern default), the cookie is not sent on the cross-site framed request, and the clickjack fails. Verify the victim's authenticated state carries into the frame.
  • The target is a state-changing action (transfer, settings/email/password change, 2FA disable, OAuth authorize, admin action), not a read-only page.

Strategy: target the most sensitive action pages first — severity scales directly with what the victim is tricked into doing.

False Positives

  • Public, read-only pages (home/marketing) lacking frame protection are low/informational — no sensitive action to redress.
  • APIs and non-HTML endpoints (JSON, images) are not clickjacking targets.
  • Header-absence alone is NOT a finding. SameSite cookies, framebusting JS, or the lack of any sensitive framed action can each fully defeat it — which is why Step 2 is mandatory.

Proof Requirements

A valid clickjacking report shows: (1) the target page rendered inside an attacker-controlled iframe in a real browser, (2) a sensitive state-changing action reachable by a framed click while the victim is authenticated (cookies survive the cross-site context), and (3) a screenshot/recording of the overlay. Reporting missing headers with no working frame PoC is a documentation-quality issue, not a vulnerability.

How to use it

Copy the folder

Take elementalsouls/hunt-clickjacking from the repository into ~/.claude/skills for personal use, or into .claude/skills inside a project.

Check the name does not clash

The agent identifies a skill by the name field in its header. Two skills with the same name cannot sit side by side — one of them will be ignored.