一些朋友在大学里是同班同学。他们发现教授把所有的作业答案都贴出来了，甚至包括那些还没有交作业、还没有打分、甚至还没有布置的作业。教授只是把它们的链接或解决方案嵌入到课程网页中，并将它们注释在HTML注释中，直到作业被收集和评分。

因为用户名和密码是相同的，这是发生在生产网站而不是测试版本。

public class AuthenticationServlet extends HttpServlet
{
    private String userName;
    private String password;

    protected doPost(HttpServletRequest req, HttpServletResponse resp)
           throws ServletException, IOException
    {
        userName = request.getParameter("userName");
        password = request.getParameter("password");
        authenticateUser(userName,password);
        ......
    }
}

显然，正如有人在自动化负载测试中发现的那样，单例和缺乏同步会导致安全问题。

我最后工作的公司的FTP用户名和密码与他们的域名相同。他们不太在意反复警告。

不用说，网站没过多久就倒闭了。没有在线备份，所以他们不得不重建整个系统。但这并没有结束。这次事件后的新安全密码是一样的…加上123。

将用户名列表以明文形式发送给浏览器以供JavaScript自动补全，还可以通过使用唯一的用户id调整URL查询字符串来查看用户数据，这可以从自动补全功能中收集到。

Right at the start of the .com era, I was working for a large retailer overseas. We watched with great interest as our competitors launched an online store months before us. Of course, we went to try it out... and quickly realized that our shopping carts were getting mixed up. After playing with the query string a bit, we realized we could hijack each other's sessions. With good timing, you could change the delivery address but leave the payment method alone... all that after having filled the cart with your favorite items.