Further XSS fixes in link attrs (#703)#705
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Nice work, unfortunately the fuzzer found another bypass on this new branch 😅 Input: ![](`<A B="
" onerror="alert(origin)">`)Output: <p><img src="code><A B="
" onerror="alert(origin)"></code" alt="" /></p> |
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Further fixes for #703, specifically the follow up issues raised in this comment: #703 (comment)
Issue 1:
For some reason html encoded colons function as normal colons in hrefs, so
javascript:alert()is equal tojavascript:alert().Fixed this by checking for these sequences alongside colons.
Issue 2:
The safe_href regex we use allows for URL domains with ports. This was intended for links like
localhost:880/abcdefbut could be abused by making the JS look like a domain with a port, like so:Issue 3:
This used some quirky markdown in a image title attr to escape the link. Fixed by hashing the title attr to prevent reprocessing, much like we do with
alt=