- name
- hunt-clickjacking
- description
- 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.
- sources
- hackerone_public, public_research
- report_count
- 6
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 aSec-Fetch-Dest/JS frame check).