webapp/bookstack
1
0
Fork 0
mirror of https://github.com/BookStackApp/BookStack.git synced 2025-08-09 10:22:51 +03:00
Code Activity

Widened svg content attribute xss filtering

Browse Source 
Takes care of additional cases that can occur.
Closes #3705
This commit is contained in:
Dan Brown
2022-09-06 17:01:56 +01:00
parent 24f82749ff
commit 6955b2fd5a
2 changed files with 7 additions and 3 deletions
Download Patch File Download Diff File Expand all files Collapse all files

7
app/Util/HtmlContentFilter.php
View File

@@ -45,10 +45,11 @@ class HtmlContentFilter
$badIframes = $xPath->query('//*[' . static::xpathContains('@src', 'data:') . '] | //*[' . static::xpathContains('@src', 'javascript:') . '] | //*[@srcdoc]');
static::removeNodes($badIframes);
// Remove tags hiding JavaScript or data uris in values attribute.
// Remove attributes, within svg children, hiding JavaScript or data uris.
// A bunch of svg element and attribute combinations expose xss possibilities.
// For example, SVG animate tag can exploit javascript in values.
$badValuesTags = $xPath->query('//*[' . static::xpathContains('@values', 'data:') . '] | //*[' . static::xpathContains('@values', 'javascript:') . ']');
static::removeNodes($badValuesTags);
$badValuesAttrs = $xPath->query('//svg//@*[' . static::xpathContains('.', 'data:') . '] | //svg//@*[' . static::xpathContains('.', 'javascript:') . ']');
static::removeAttributes($badValuesAttrs);
// Remove elements with a xlink:href attribute
// Used in SVG but deprecated anyway, so we'll be a bit more heavy-handed here.