HeyForm is an open-source form builder. Prior to version 3.0.0-rc.9, POST /api/upload has no authentication guard, no global guard, no form-context validation, no openToken requirement, and no session cookie check. Any anonymous internet user can upload files (PDF, DOC/DOCX, XLS/XLSX, CSV, TXT, MP4, images, etc., up to 10 MB) and receive a permanent public URL on the HeyForm domain. The endpoint is used by both authenticated form creators and unauthenticated form submitters; because no form-context binding exists, every request to it is anonymously accepted. Version 3.0.0-rc.9 contains a patch for the issue.
Exploitability
AV:NAC:LPR:NUI:NScope
S:UImpact
C:LI:HA:L8.6/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:LAuthentication
Other