DevMeth
C21

Input handling

Upload Endpoint Check — Does Your Upload Accept Any File, No Limits?

DevMeth checks the 48 known AI-code failure patternsnot a penetration test or a security guarantee.

What the issue is

An upload endpoint that accepts any file with no type filter or size limit can be abused to push malware, exhaust disk, or overwrite files on your server.

Why AI tools generate it

AI tools scaffold a working upload with no constraints so the feature demonstrably works, leaving out the file-type filter and size cap.

How DevMeth detects it

A code scan checks upload-library calls for a file-type filter and a size limit, flagging any that accept files unconstrained.

C21
What a finding looks like
High

Your upload endpoint accepts any file, no limits

WHAT WE FOUND

upload routeno file-type filter or size limit

Sample — illustrative and masked exactly as a real report shows it. Run a free scan to see your own results.

The fix, in three steps

Add an allowlist of allowed file types and a hard size limit to every upload path, and never trust the client's claimed type. Three steps.

Run a free scan and each finding carries a paste-ready fix prompt you can act on.

Try a free scan

FAQ

What can go wrong with unrestricted uploads?

Malware or executable uploads, disk exhaustion from oversized files, or overwriting server paths if the filename is unvalidated.

What is detected?

Upload-library calls lacking a file-type filter or a size limit are flagged as an unrestricted-upload candidate.

What's the fix?

Allowlist file types, enforce a hard size limit, and validate the actual content — never the client's claimed type.

DevMeth checks the 48 known AI-code failure patternsnot a penetration test or a security guarantee. A clear result means each known pattern was checked and found clear or not applicable for your app; it is not a guarantee of security.