HTMLencode处理QQ空间缺陷导致日志存储型XSS

 　　1. 接着看这个系列的第一个漏洞(content_gridsblog.js)中那部分的代码。

　　腾讯为了修复这个漏洞，采用了更为安全的JSON.parse函数作为修复方案。这种修复是没有问题的。

　　其它有类似缺陷的网站可以参考腾讯的修复方案。

　　2. 但实际上，在这段代码下方的不远处，还存在着另外一处缺陷，如下图所示：

　　可以看到， oGridInfo为 JSON.parse解析出来的一个[Object]

　　而 oGridInfo.templateName 取出来后，没有经过任何过滤，就传入到了 innerHTML 中。

　　而从抓包的数据来看，json数据里的templateName 我们是可控的，那么这里就显然存在问题啦～

　　3. 修改日志数据包中的templateName，并发送。

{"g0":{"visible":1,"id":0,"content":{"mood":"","image":"","date":"","text":"1"},"type":1,"title":"?????????"},"g5":{"visible":1,"id":5,"content":{"mood":"","image":"","date":"","text":"1"},"type":1,"title":"2012?????????"},"g1":{"visible":1,"id":1,"content":{"mood":"","image":"","date":"","text":"1"},"type":1,"title":"???????"},"templateName":"
","g4":{"visible":1,"id":4,"content":{"mood":"","image":"","date":"2013-03-20&1","text":""},"type":0,"title":"???? 2013-3-20"},"g7":{"visible":1,"id":7,"content":{"mood":"","image":"","date":"","text":"1"},"type":1,"title":"??????????"},"version":"1.2","g2":{"visible":1,"id":2,"content":{"mood":"","image":"","date":"","text":"1"},"type":1,"title":"??????"},"bgItem":{"bgId":"130","bgURL":"/qzone/newblog/v5/flashassets/bg130.swf?bgver=1.0&max_age=31104000","gridcolor":"0xF06368","alpha":1,"align":"right","wordcolor":"0xFFFFFF"},"tempId":56,"g8":{"visible":1,"id":8,"content":{"mood":"","image":"","date":"","text":"1"},"type":1,"title":"???????????"},"g6":{"visible":1,"id":6,"content":{"mood":"","image":"","date":"","text":"1"},"type":1,"title":"????????????"},"g3":{"visible":1,"id":3,"content":{"mood":"","image":"","date":"","text":"1"},"type":1,"title":"2012?????????"}}

　　4. 用另外一个号，查看已经发表的日志。 成功弹出啦。

　　由于代码逻辑上，只有他人查看日志时，才会触发此段代码，故测试时，请以第三者身份查看包含缺陷代码的日志

　　修复方案：

　　oGridInfo.templateName取出后，HTMLencode一下。

关键词：