Published 11 years 4 months ago • Last updated March 22, 2025 • ⏱️ < 1 min read
This bug is similar to the last one I posted but executes in a different context. It requires an existing script after the injection because we use it to close the injected script. It's a shame chrome doesn't support self closing scripts in HTML or within a SVG element because I'm pretty sure I could bypass it without using an existing script. Anyway the injection uses a data url with a script. In order to bypass the filter we need to concat the string with the quote from the attribute or use html entities such as //. The HTML parser doesn't care how much junk is between the opening and closing script since we are using a src attribute.