tonyair
/
silverstripe-framework
mirror of https://github.com/silverstripe/silverstripe-framework
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

[CVE-2022-28803] Block XSS in links and iframes.

This commit is contained in:
Guy Sartorelli 2022-04-19 15:11:30 +12:00 committed by Steve Boyd
parent 0bc3ed4d2c
commit d2c58f3bbc
2 changed files with 35 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
src/Forms/HTMLEditor/HTMLEditorSanitiser.php
View File

@ -345,6 +345,17 @@ class HTMLEditorSanitiser
foreach ($elementRule->attributesForced as $attr => $forced) {
$el->setAttribute($attr, $forced);
}
// Matches "javascript:" with any arbitrary linebreaks inbetween the characters.
$regex = '/^\s*' . implode('\v*', str_split('javascript:')) . '/';
// Strip out javascript execution in href or src attributes.
foreach (['src', 'href'] as $dangerAttribute) {
if ($el->hasAttribute($dangerAttribute)) {
if (preg_match($regex, $el->getAttribute($dangerAttribute))) {
$el->removeAttribute($dangerAttribute);
}
}
}
}
if ($el->tagName === 'a' && $linkRelValue !== null) {

24
tests/php/Forms/HTMLEditor/HTMLEditorSanitiserTest.php
View File

@ -74,6 +74,30 @@ class HTMLEditorSanitiserTest extends FunctionalTest
'<a href="/test" target="_blank">Test</a>',
'noopener rel attribute is unchanged when link_rel_value is null'
],
[
'a[href|target|rel]',
'<a href="javascript:alert(0);">Test</a>',
'<a>Test</a>',
'Javascript in the href attribute of a link is completely removed'
],
[
'a[href|target|rel]',
'<a href="' . implode("\n", str_split(' javascript:')) . '">Test</a>',
'<a>Test</a>',
'Javascript in the href attribute of a link is completely removed even for multiline markup'
],
[
'map[name],area[href|shape|coords]',
'<map name="test"><area shape="rect" coords="34,44,270,350" href="javascript:alert(0);"></map>',
'<map name="test"><area shape="rect" coords="34,44,270,350"></map>',
'Javascript in the href attribute of a map\'s clickable area is completely removed'
],
[
'iframe[src]',
'<iframe src="javascript:alert(0);"></iframe>',
'<iframe></iframe>',
'Javascript in the src attribute of an iframe is completely removed'
],
];
$config = HTMLEditorConfig::get('htmleditorsanitisertest');