Fix XSS issue in safe mode (#601) #602
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This PR fixes #601 by making the HTML tokenisation regex more lenient.
Currently, the regex matches HTML tags and their attributes, using
[\w-]for the attribute name. However, in the HTML spec it says:The current character class being used does not include all these possibilities so I've updated it to instead exclude these banned characters:
[^<>"'=/].I also tweaked how the attribute values are matched. The current regex only allows for quoted values, which lets
src=# onerror=alert()slip past. I've added another clause in the regex that matches unquoted attr values as long as they don't contain a space (because that would count as the next attribute)