Skills

Hunt Clickjacking

Hunt Clickjacking, missing X-Frame-Options / CSP frame-ancestors lets an attacker...

Install

npx skills add elementalsouls/Claude-BugHunter --skill hunt-clickjacking -g -a claude-code -y
Category
Design
Updated
3d ago
License
MIT
Context cost
Lightabout 894 tokens
Runs scripts
No, instructions only

What it does

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.

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:

Read the whole SKILL.md on GitHub

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