🔒 修复分享列表接口的目录遍历漏洞

- 在 /api/share/:code/list 增加路径规范化与范围校验
- 使用 path.posix.normalize 处理 subPath，阻断 ../ 遍历攻击
- 调用 isPathWithinShare 验证请求路径在分享范围内
- 统一使用安全的 requestedPath 进行存储访问和直链生成

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

backend/server.js

@@ -2902,6 +2902,20 @@ app.post('/api/share/:code/list', shareRateLimitMiddleware, async (req, res) =>
       });
     }
 
+    // 构造安全的请求路径，防止越权遍历
+    const baseSharePath = (share.share_path || '/').replace(/\\/g, '/');
+    const requestedPath = subPath
+      ? path.posix.normalize(`${baseSharePath}/${subPath}`)
+      : baseSharePath;
+
+    // 校验请求路径是否在分享范围内
+    if (!isPathWithinShare(requestedPath, share)) {
+      return res.status(403).json({
+        success: false,
+        message: '无权访问该路径'
+      });
+    }
+
     // 使用统一存储接口，根据分享的storage_type选择存储后端
     const { StorageInterface } = require('./storage');
     const storageType = share.storage_type || 'sftp';
@@ -2957,14 +2971,13 @@ app.post('/api/share/:code/list', shareRateLimitMiddleware, async (req, res) =>
     }
     // 如果是目录分享（分享所有文件）
     else {
-      const fullPath = subPath ? `${share.share_path}/${subPath}`.replace('//', '/') : share.share_path;
-      const list = await storage.list(fullPath);
+      const list = await storage.list(requestedPath);
 
       formattedList = list.map(item => {
         // 构建完整的文件路径用于下载
         let httpDownloadUrl = null;
         if (storageType === 'sftp' && sanitizedShareHttpBase && item.type !== 'd') {
-          const normalizedPath = fullPath.startsWith('/') ? fullPath : `/${fullPath}`;
+          const normalizedPath = requestedPath.startsWith('/') ? requestedPath : `/${requestedPath}`;
           const filePath = normalizedPath === '/' ? `/${item.name}` : `${normalizedPath}/${item.name}`;
           httpDownloadUrl = buildHttpDownloadUrl(sanitizedShareHttpBase, filePath);
         }