BREAKING DOWN MULTIPART PARSERS: FILE UPLOAD VALIDATION BYPASS

Summary from the TLDR InfoSec newsletter

Parsers often fail to fully comply with RFC standards, allowing for various ways to bypass file upload validation. Techniques like altering headers, duplicating parameters, and manipulating content types can deceive validation mechanisms. Attackers can slip malicious inputs past security measures by exploiting loopholes in parsers' handling of multipart data.