但是有个安全网站的某个地址只做重定向，而且不进行任何内部判断（或者说是安全判断），那么只要将不安全网站作为其参数，就可以绕开钓鱼网站判定机制。如：
浏览该地址，的确会在安全网站上做一次操作，但是将完成一个重定向动作，重定向结果将是不安全网站。
这样的情况会发生在登录的情况，有的登录界面会有一个ReturnUrl作为参数标识。
按照正常的流程，将会在登录成功后跳转到default.aspx页面，但是如果将这里写为重定向到一个伪安全页面，如：
那么在登录后，将会见到一个非安全的页面，而这时候用户通常难以察觉或者已经中招。（病毒/钓鱼/骗流量等）
总结
在站点中通过URL参数做重定向，将直接给非法网站提供机会。
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="WebAppUnsafeRedirect._Default" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>Unsafe Redirect</title>
</head>
<script runat="server">
private void btnLogin_Click(object sender, EventArgs e)
{
if (CheckUser(txtUsername.Text, txtPassword.Text))
{
string redirectUrl = Request.QueryString["ReturnUrl"] ?? "http://volnet.cnblogs.com?key=demo-unsafe-redirect";
Response.Redirect(redirectUrl);
}
}
</script>
<body>
<form id="form1" runat="server">
<div>
<asp:TextBox ID="txtUsername" runat="server"></asp:TextBox><br />
<asp:TextBox ID="txtPassword" runat="server" TextMode="Password"></asp:TextBox><br />
<asp:Button ID="btnLogin" runat="server" Text="Login"
onclick="btnLogin_Click" /><br />
</div>
</form>
</body>
<script runat="server">
private bool CheckUser(string userName, string password)
{
if (userName == "User1" && password == "Password")
{
return true;
}
return false;
}
</script>
</html>
原文链接：https://www.cnblogs.com/volnet/archive/2009/07/29/unsafe-redirect.html
原创文章，作者：优速盾-小U，如若转载，请注明出处：https://www.cdnb.net/bbs/archives/17712
评论列表（1条）
I believe what you posted was very logical. However, what about this?
what if you were to write a killer post title?
I mean, I don’t wish to tell you how to run your website, but suppose you added a title to
possibly grab people’s attention? I mean [网站安全]避免在站点中通过URL参数做重定向
– 优速盾 is kinda vanilla. You might glance at Yahoo’s home page and note
how they create news headlines to grab people to click.
You might add a related video or a related pic or two to get people excited about what you’ve got to say.
In my opinion, it might make your website a little
bit more interesting.