The description above is MITRE’s definition of CWE-939 in CWE 4.20, a base-level weakness.
Common consequences MITRE lists
- Access Control, Other: Gain Privileges or Assume Identity; Varies by Context; Bypass Protection Mechanism
Guides on this site
Review trust boundaries in mobile and native clients
Protect local data and platform interactions while keeping server-side authorization independent of the client’s behavior.
Review mobile storage, links and platform permissions
Keep local artifacts and platform entry points from exposing authority that belongs on the server.
Harden an Android app's storage, network and entry points
Encrypt local secrets with Android Keystore keys now that Jetpack Security is deprecated, set transport policy in Network Security Configuration, close exported components and mutable PendingIntents, confine WebViews, verify App Links and judge Play Integrity verdicts on the server, mapped to OWASP MASVS 2.1.
Harden an iOS app's storage, network and entry points
Store secrets in the Keychain with the narrowest accessibility class, set file protection explicitly, keep App Transport Security on, prefer universal links, constrain WKWebView bridges, keep step-up keys in the Secure Enclave, verify App Attest on the server and ship an accurate privacy manifest, mapped to OWASP MASVS 2.1.
Practice
- Keep an iOS app's storage, links and web bridge in bounds · Local project
- Repair an Android app's links, components, network policy and storage · Local project
References
This page is generated from MITRE’s CWE 4.20 catalogue (released 30 April 2026) and lists every guide, fix card and lab here that cites CWE-939.
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