---
name: elementalsouls/hunt-clickjacking
source: https://app.decimal.ai/s/elementalsouls-hunt-clickjacking@1/SKILL.md
source_sha256: 766fb80c0e30
---
## 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:
```html
Win a prize — click below
```
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.