> For the complete documentation index, see [llms.txt](https://hacking-notes.jord4n.pro/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://hacking-notes.jord4n.pro/zh/web/cors/cors-null-origin-trusted.md).
# CORS 信任 null 源
CORS 信任 null 源笔记，适用于 PortSwigger Web Security Academy 实验室，包括利用流程、载荷测试、Burp Suite 验证和修复上下文。
### 具有受信任 null 源的 CORS 漏洞
利用一个信任原始来源的易受攻击的 CORS 配置 `"null"`。本实验的目标是通过一个 CORS 请求从管理员处检索 API 密钥（使用 `凭据`）并将代码上传到利用服务器。当管理员的 API 密钥成功提交时，实验即告完成。
* 服务器返回 `Access-Control-Allow-Credentials: true`.
当 `Origin: jord4n.pro` 标头被发送时，域名不会被反射。
然而，当发送 `Origin: null`时，响应会接受并反射该值。
强制从一个页面发起请求，页面的 `null` 源（例如通过 `iframe` 中的文件内容，使用 `srcdoc`），这样 CORS 响应会认为该源可信并返回数据（使用以下方式的 cookie： `withCredentials`).
```javascript
```
> 注意：原理是从 `null` 源（iframe `srcdoc`），这样接受 `null`的 CORS 响应会返回敏感数据，包括 cookie。
恢复的密钥，Base64 解码后：
```bash
echo "NkhBVGdaVWdUb0t2QU5PbXNzanRyY1pDRlpUQUVFYjk=" | base64 -d; echo
6HATgZUgToKvANOmssjtrcZCFZTAEEb9
```
---
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