Unsafe upload interpretation or placement
Uploaded content is handled in a security-sensitive context beyond its permitted file contract.
Candidate CWE: CWE-434
Test hypothesis#
Use a tiny supported baseline. Change filename, declared MIME, and harmless bytes independently in a replica; inspect storage path, processing, retrieval origin, and actual rendering from controlled B.
Evidence required#
Show unsafe interpretation, prohibited placement, or a consequential parser path. Record the exact lifecycle stage and avoid claiming code execution from file acceptance alone.
Rule out false positives#
An unusual extension accepted as inert download, safe isolated hosting, or a file rejected after asynchronous processing is not executable-upload proof.
Playbook and command references#
- Uploads, downloads, paths, archives, and XML — Follow a file through acceptance, storage, processing, publication, and retrieval while preserving ownership and path boundaries.
- Browser execution, cross-origin reads, and forged actions — Use real browser behavior to distinguish XSS, CSRF, CORS, and messaging failures from header-only leads.
Find the associated command snippets
Referenced by these target playbooks#
Report checklist#
- Capture the affected version, configuration, identities, and object ownership.
- Preserve a valid baseline and a negative control.
- Reproduce the forbidden data access, action, or state change on controlled fixtures.
- Explain the intended security rule and why the observed behavior violates it.
- State prerequisites, uncertainty, cleanup, and the smallest demonstrated impact.
Conditional ATT&CK mapping#
No direct ATT&CK mapping selected. Record the weakness and demonstrated impact without forcing an adversary-behavior classification. See the mapping guide.