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Changeset 46899


Ignore:
Timestamp:
12/12/2019 06:10:23 PM (18 months ago)
Author:
whyisjake
Message:

Update wp_kses_bad_protocol() to recognize : on uri attributes,

wp_kses_bad_protocol() makes sure to validate that uri attributes don’t contain invalid/or not allowed protocols. While this works fine in most cases, there’s a risk that by using the colon html5 named entity, one is able to bypass this function.

Brings r46895 to the 5.3 branch.

Props: xknown, nickdaugherty, peterwilsoncc.

Location:
branches/5.3
Files:
2 edited

Legend:

Unmodified
Added
Removed
  • branches/5.3/src/wp-includes/kses.php

    r46794 r46899  
    16661666function wp_kses_bad_protocol_once( $string, $allowed_protocols, $count = 1 ) {
    16671667    $string  = preg_replace( '/(&#0*58(?![;0-9])|&#x0*3a(?![;a-f0-9]))/i', '$1;', $string );
    1668     $string2 = preg_split( '/:|&#0*58;|&#x0*3a;/i', $string, 2 );
     1668    $string2 = preg_split( '/:|&#0*58;|&#x0*3a;|:/i', $string, 2 );
    16691669    if ( isset( $string2[1] ) && ! preg_match( '%/\?%', $string2[0] ) ) {
    16701670        $string   = trim( $string2[1] );
  • branches/5.3/tests/phpunit/tests/kses.php

    r46794 r46899  
    180180        }
    181181
     182        $bad_not_normalized = array(
     183            'dummy:alert(1)',
     184            'javascript:alert(1)',
     185            'javascript&CoLon;alert(1)',
     186            'javascript:alert(1);',
     187            'javascript:alert(1);',
     188            'javascript:alert(1);',
     189            'javascript&#0000058alert(1);',
     190            'jav    ascript:alert(1);',
     191            'javascript:javascript:alert(1);',
     192            'javascript:javascript:alert(1);',
     193            'javascript&#0000058javascript:alert(1);',
     194            'javascript:javascript&#0000058alert(1);',
     195            'javascript&#58alert(1)',
     196        );
     197        foreach ( $bad_not_normalized as $k => $x ) {
     198            $result = wp_kses_bad_protocol( $x, wp_allowed_protocols() );
     199            if ( ! empty( $result ) && 'alert(1);' !== $result && 'alert(1)' !== $result ) {
     200                $this->fail( "wp_kses_bad_protocol failed on $k, $x. Result: $result" );
     201            }
     202        }
     203
    182204        $safe = array(
    183205            'dummy:alert(1)',
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