PHP5.1.6、4.4.4及以前版本中，在查找关于“htmlspecialchars() and htmlentities() ”相关字符编码的时候，当UTF-8编码被选择的时候可能会触发一个可能的缓冲器溢出。
“While we were searching for a hole in htmlspecialchars() and htmlentities() to bypass the encoding of certain chars to exploit a possible eval() injection hole in another application we discovered that the implementation contains a possible bufferoverflow that can be triggered when the UTF-8 charset is selected.”
最新发行的PHP5版本5.2已经修正了这个错误，但是该问题仍然在PHP4.4 版本中存在。全部信息可以在the full vulnerability 查看到