Risk: High
Vulnerabilities recently reported in PHP can be exploited to cause a Denial of Service or compromise a vulnerable system.
The vulnerabilities exist because of boundary errors within the "htmlentities()" and "htmlspecialchars()" functions. If user-supplied information is processed by a PHP application that uses these functions, it can be exploited by passing specially crafted data to the application, which could cause a heap-based buffer overflow.
If the UTF-8 character set is selected, successful exploitation could also allow execution of arbitrary code.