diff options
| -rwxr-xr-x | system/core/Security.php | 91 |
1 files changed, 41 insertions, 50 deletions
diff --git a/system/core/Security.php b/system/core/Security.php index dcc680a11..a3e227437 100755 --- a/system/core/Security.php +++ b/system/core/Security.php @@ -77,7 +77,8 @@ class CI_Security { '-moz-binding' => '[removed]', '<!--' => '<!--', '-->' => '-->', - '<![CDATA[' => '<![CDATA[' + '<![CDATA[' => '<![CDATA[', + '<comment>' => '<comment>' ); /* never allowed, regex replacement */ @@ -475,15 +476,7 @@ class CI_Security { { if ($this->_xss_hash == '') { - if (phpversion() >= 4.2) - { - mt_srand(); - } - else - { - mt_srand(hexdec(substr(md5(microtime()), -8)) & 0x7fffffff); - } - + mt_srand(); $this->_xss_hash = md5(time() + mt_rand(0, 1999999999)); } @@ -497,14 +490,11 @@ class CI_Security { * * This function is a replacement for html_entity_decode() * - * In some versions of PHP the native function does not work - * when UTF-8 is the specified character set, so this gives us - * a work-around. More info here: - * http://bugs.php.net/bug.php?id=25670 - * - * NOTE: html_entity_decode() has a bug in some PHP versions when UTF-8 is the - * character set, and the PHP developers said they were not back porting the - * fix to versions other than PHP 5.x. + * The reason we are not using html_entity_decode() by itself is because + * while it is not technically correct to leave out the semicolon + * at the end of an entity most browsers will still interpret the entity + * correctly. html_entity_decode() does not convert entities without + * semicolons, so we are left with our own little solution here. Bummer. * * @param string * @param string @@ -512,33 +502,14 @@ class CI_Security { */ public function entity_decode($str, $charset='UTF-8') { - if (stristr($str, '&') === FALSE) return $str; - - // The reason we are not using html_entity_decode() by itself is because - // while it is not technically correct to leave out the semicolon - // at the end of an entity most browsers will still interpret the entity - // correctly. html_entity_decode() does not convert entities without - // semicolons, so we are left with our own little solution here. Bummer. - - if (function_exists('html_entity_decode') && - (strtolower($charset) != 'utf-8')) - { - $str = html_entity_decode($str, ENT_COMPAT, $charset); - $str = preg_replace('~&#x(0*[0-9a-f]{2,5})~ei', 'chr(hexdec("\\1"))', $str); - return preg_replace('~&#([0-9]{2,4})~e', 'chr(\\1)', $str); - } - - // Numeric Entities - $str = preg_replace('~&#x(0*[0-9a-f]{2,5});{0,1}~ei', 'chr(hexdec("\\1"))', $str); - $str = preg_replace('~&#([0-9]{2,4});{0,1}~e', 'chr(\\1)', $str); - - // Literal Entities - Slightly slow so we do another check if (stristr($str, '&') === FALSE) { - $str = strtr($str, array_flip(get_html_translation_table(HTML_ENTITIES))); + return $str; } - return $str; + $str = html_entity_decode($str, ENT_COMPAT, $charset); + $str = preg_replace('~&#x(0*[0-9a-f]{2,5})~ei', 'chr(hexdec("\\1"))', $str); + return preg_replace('~&#([0-9]{2,4})~e', 'chr(\\1)', $str); } // -------------------------------------------------------------------- @@ -632,25 +603,45 @@ class CI_Security { protected function _remove_evil_attributes($str, $is_image) { // All javascript event handlers (e.g. onload, onclick, onmouseover), style, and xmlns - $evil_attributes = array('on\w*', 'style', 'xmlns'); + $evil_attributes = array('on\w*', 'style', 'xmlns', 'formaction'); if ($is_image === TRUE) { /* - * Adobe Photoshop puts XML metadata into JFIF images, + * Adobe Photoshop puts XML metadata into JFIF images, * including namespacing, so we have to allow this for images. */ unset($evil_attributes[array_search('xmlns', $evil_attributes)]); } - + do { - $str = preg_replace( - "#<(/?[^><]+?)([^A-Za-z\-])(".implode('|', $evil_attributes).")(\s*=\s*)([\"][^>]*?[\"]|[\'][^>]*?[\']|[^>]*?)([\s><])([><]*)#i", - "<$1$6", - $str, -1, $count - ); - } while ($count); + $count = 0; + $attribs = array(); + + // find occurrences of illegal attribute strings without quotes + preg_match_all("/(".implode('|', $evil_attributes).")\s*=\s*([^\s]*)/is", $str, $matches, PREG_SET_ORDER); + + foreach ($matches as $attr) + { + $attribs[] = preg_quote($attr[0], '/'); + } + + // find occurrences of illegal attribute strings with quotes (042 and 047 are octal quotes) + preg_match_all("/(".implode('|', $evil_attributes).")\s*=\s*(\042|\047)([^\\2]*?)(\\2)/is", $str, $matches, PREG_SET_ORDER); + foreach ($matches as $attr) + { + $attribs[] = preg_quote($attr[0], '/'); + } + + // replace illegal attribute strings that are inside an html tag + if (count($attribs) > 0) + { + $str = preg_replace("/<(\/?[^><]+?)([^A-Za-z\-])(".implode('|', $attribs).")([\s><])([><]*)/i", '<$1$2$4$5', $str, -1, $count); + } + + } while ($count); + return $str; } |