Uses a list of CSS properties and functions that use CSP violations to determine which properties/functions cause external requests.
<div style="$[data1]:$[data2]('https://fuzz.shazzer.co.uk/$[rand]?$[data1]->$[data2]')"></div><div style="-webkit-mask-box-image->image-set:('https://fuzz.shazzer.co.uk/vpm2dbir1fj?-webkit-mask-box-image->image-set->')"></div><div style="-webkit-mask-box-image->url:('https://fuzz.shazzer.co.uk/o35q4reudh?-webkit-mask-box-image->url->')"></div><div style="-webkit-mask-box-image->-webkit-image-set:('https://fuzz.shazzer.co.uk/itj0xa331o?-webkit-mask-box-image->-webkit-image-set->')"></div><div style="-webkit-mask-box-image-source->image-set:('https://fuzz.shazzer.co.uk/9mmi5l9lz2e?-webkit-mask-box-image-source->image-set->')"></div><div style="-webkit-mask-box-image-source->url:('https://fuzz.shazzer.co.uk/f8nv4qzsydc?-webkit-mask-box-image-source->url->')"></div><div style="-webkit-mask-box-image-source->-webkit-image-set:('https://fuzz.shazzer.co.uk/vverrdrnsdj?-webkit-mask-box-image-source->-webkit-image-set->')"></div><div style="background->image-set:('https://fuzz.shazzer.co.uk/kxxsh293fp?background->image-set->')"></div><div style="background->url:('https://fuzz.shazzer.co.uk/96xrs8x5hfw?background->url->')"></div><div style="background->-webkit-image-set:('https://fuzz.shazzer.co.uk/tjggahi3fy9?background->-webkit-image-set->')"></div><div style="background-image->image-set:('https://fuzz.shazzer.co.uk/qereziwx1g?background-image->image-set->')"></div><div style="background-image->url:('https://fuzz.shazzer.co.uk/0rw926vcmkip?background-image->url->')"></div><div style="background-image->-webkit-image-set:('https://fuzz.shazzer.co.uk/dteyghvtm8t?background-image->-webkit-image-set->')"></div><div style="border-image->image-set:('https://fuzz.shazzer.co.uk/4y7l5dvddmp?border-image->image-set->')"></div><div style="border-image->url:('https://fuzz.shazzer.co.uk/dpyt2k4voqm?border-image->url->')"></div><div style="border-image->-webkit-image-set:('https://fuzz.shazzer.co.uk/klw1syx13zm?border-image->-webkit-image-set->')"></div><div style="border-image-source->image-set:('https://fuzz.shazzer.co.uk/arlwxf4rcr6?border-image-source->image-set->')"></div><div style="border-image-source->url:('https://fuzz.shazzer.co.uk/hkv0srztc8?border-image-source->url->')"></div><div style="border-image-source->-webkit-image-set:('https://fuzz.shazzer.co.uk/nnrokp9nh4?border-image-source->-webkit-image-set->')"></div><div style="clip-path->url:('https://fuzz.shazzer.co.uk/ekpsj6ekx15?clip-path->url->')"></div><div style="content->image-set:('https://fuzz.shazzer.co.uk/faad3kcozbu?content->image-set->')"></div>