Bug: HTTP Method Override Works on API
Author: 0xNexarCreated Aug 9, 2025Updated Mar 3, 2026
LabelsC-bugA-appP-high
HTTP Method Override Vulnerability
Summary
API accepts HTTP Method Override headers, allowing bypass of method-based security controls.
Affected System
- API: https://api.dashboard.union.build/rest/v1/
- Endpoints: /wallets, /user_achievements, /chains, /user_points
Proof of Concept
Normal DELETE (blocked): curl -X DELETE "https://api.dashboard.union.build/rest/v1/wallets" -H "apikey: [KEY]"
Returns: 405 Method Not Allowed
Override DELETE (processed):
curl -X POST "https://api.dashboard.union.build/rest/v1/wallets"
-H "X-HTTP-Method-Override: DELETE"
-H "apikey: [KEY]"
Returns: 400 Bad Request (server processes override)
Impact
- Bypasses HTTP method-based security controls
- Could affect dashboard (XP/leaderboard manipulation attempts)
- Multiple override headers work: X-HTTP-Method-Override, X-Method-Override, _method
Evidence
Response code difference (405 vs 400) proves server processes override methods instead of blocking them.
Source: unionlabs/union