Mobile link handler trusts routing as authorization
An externally supplied custom or universal/app link reaches a protected client operation without validating the route input and current security context.
Candidate CWE: CWE-939 · CWE-863
Test hypothesis#
Open a known benign link, then vary one resource or callback parameter across logged-out/account-switched states. Keep callbacks and test objects owned.
Evidence required#
Exact URL, OS routing, eligible build, current account, handler path and resulting protected capability; document callback verification when relevant.
Rule out false positives#
A verified domain association does not prove parameter safety. A custom scheme existing or a public route opening is not a vulnerability by itself.
Playbook and command references#
- Android components, intents and deep links — Trace ordinary-app inputs through exported components, URI grants and links to one protected operation.
- iOS signing capabilities, links and protected data — Connect entitlements and application groups to actual callers, URL transitions and protected key use.
- Authentication, recovery, federation, and session lifecycle — Test registration, recovery, identity changes, invitations, SSO enforcement, and deprovisioning as one account state machine.
- Object, function, and property authorization — Turn identities, tenants, objects, roles, and lifecycle transitions into a reproducible permission matrix.
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.