SRC漏洞小技巧——文件上传垃圾漏洞之绕过上传大小

原创于 2025-08-20 14:52:08 发布 · 689 阅读

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在日常渗透测试中会发现有的上传功能的地方会限制上传大小，例如15M，如果绕过前端的这个提示，使用BURP抓包超大包 BURP会特别卡，导致无法发送，因此写了个小html和py来传输数据。

如下图所示可能会遇到这类功能

在这里插入图片描述

前端HTML代码

<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <title>文件上传演示（代理版）</title>
    <style>
        /* 样式保持不变 */
        body {
            font-family: Arial, sans-serif;
            max-width: 600px;
            margin: 20px auto;
            padding: 20px;
        }
        .upload-box {
            border: 2px dashed #ccc;
            padding: 30px;
            text-align: center;
            margin: 20px 0;
        }
        #status {
            margin-top: 15px;
            padding: 10px;
            border-radius: 4px;
        }
.input-group {
margin: 10px 0;
text-align: left;
	}

.input-group label {
display: block;
margin-bottom: 5px;
color: #666;
		}

.input-group input {
width: 100%;
padding: 8px;
border: 1px solid #ddd;
border-radius: 4px;
box-sizing: border-box;
		}

        .success { background: #dff0d8; color: #3c763d; }
        .error { background: #f2dede; color: #a94442; }
    </style>
</head>
<body>
    <h2>文件上传演示</h2>

<div class="upload-box">
    <!-- 新增：Authorization输入框 -->
    <div class="input-group">
        <label for="authInput">Authorization:</label>
        <input type="text" id="authInput" placeholder="Bearer token (可选)">
    </div>

    <!-- 新增：Cookie输入框 -->
    <div class="input-group">
        <label for="cookieInput">Cookie:</label>
        <input type="text" id="cookieInput" placeholder="Cookie值 (可选)">
    </div>

    <input type="file" id="fileInput" accept=".pdf,.doc,.docx">
    <button onclick="uploadFile()">上传文件</button>
    <div id="status"></div>
</div>

    <script>
async function uploadFile() {
const fileInput = document.getElementById('fileInput');
const statusDiv = document.getElementById('status');
const authInput = document.getElementById('authInput');
const cookieInput = document.getElementById('cookieInput');

if (!fileInput.files.length) {
showStatus('请先选择文件', 'error');
return;
		}

// +++ 修复1: 确保FormData初始化 +++
const formData = new FormData();
		formData.append('dir', 'user_pri');
		formData.append('file', fileInput.files[0]);

// 构建动态Header
const headers = {};
if (authInput.value) headers['Authorization'] = authInput.value;
if (cookieInput.value) headers['Cookie'] = cookieInput.value;

try {
const response = await fetch('http://localhost:5000/upload', {
method: 'POST',
headers: headers,
body: formData // 使用已初始化的formData
			});

if (response.ok) {
const result = await response.json();
showStatus(`文件上传成功！文件名：${result.filename}`, 'success');
			} else {
showStatus(`上传失败：${response.statusText}`, 'error');
			}
		} catch (error) {
showStatus(`网络错误：${error.message}`, 'error');
		}
	}

        function showStatus(message, type) {
            const statusDiv = document.getElementById('status');
            statusDiv.className = type;
            statusDiv.textContent = message;

            setTimeout(() => {
                statusDiv.className = '';
                statusDiv.textContent = '';
            }, 3000);
        }
    </script>
</body>
</html>

python代

from flask import Flask, request
from flask_cors import CORS
import requests

app = Flask(__name__)
app.config['MAX_CONTENT_LENGTH'] = 100 * 1024 * 1024  # 允许100MB文件
CORS(app)

@app.route('/upload', methods=['POST'])
def upload():
    try:
        # 获取请求头
        auth_header = request.headers.get('Authorization', '')
        cookie_header = request.headers.get('Cookie', '')
        file = request.files['file']

        # 转发请求到目标API
        response = requests.post(
            'https://test.digifttest.com/api/file/upload',
            files={'file': (file.filename, file.stream)},
            headers={
                'Authorization': auth_header,
                'Cookie': cookie_header
            },
            data={'dir': 'user_pri'}
        )

        # 打印完整的返回包信息到控制台
        print("="*50 + " 响应详情 " + "="*50)
        print(f"状态码: {response.status_code}")
        print("\n响应头:")
        for key, value in response.headers.items():
            print(f"  {key}: {value}")
        print("\n响应体:")
        try:
            print(response.json())  # 尝试解析JSON
        except:
            print(response.text)    # 纯文本或二进制内容
        print("="*110 + "\n")

        # 返回完整响应信息
        return (
            response.content, 
            response.status_code,
            dict(response.headers)  # 携带原始响应头
        )

    except Exception as e:
        print(f"! 错误: {str(e)}")
        return {
            "error": str(e),
            "message": "代理服务器内部错误"
        }, 500

if __name__ == '__main__':
    app.run(port=5000, debug=True)  # 启用debug模式显示详细错误

填写凭据

在这里插入图片描述