Description of problem:
ext/filter in PHP 5.2.0, when FILTER_SANITIZE_STRING is used with the
FILTER_FLAG_STRIP_LOW flag, does not properly strip HTML tags, which allows
remote attackers to conduct cross-site scripting (XSS) attacks via HTML with a
'<' character followed by certain whitespace characters, which passes one filter
but is collapsed into a valid tag, as demonstrated using %0b.
The 'filter' extension is not currently included in php packages distributed by
*** Bug 239319 has been marked as a duplicate of this bug. ***