Deep links, intent extras, push payloads and server responses all reach code that may build queries, load URLs or make decisions. Treating them as trusted turns a crafted link into an injection or a bypassed check.
- Parse links and extras strictly: check the scheme, host and path against an allowlist and reject anything else.
- Use parameterized queries for local databases and safe parsers for structured data.
- Validate on the server as well; the client's checks can be bypassed.
MASTG tests in the local projects
The local projects run these OWASP MASTG v2.0.0 tests for MASVS-CODE-4, as tests you can repeat on your own machine.
| MASTG test | Platform | Project |
|---|---|---|
| MASTG-TEST-0370: Missing Input Validation in Custom URL Scheme Handlers | iOS | Keep an iOS app's storage, links and web bridge in bounds · LinkTests |
| MASTG-TEST-0395: Missing Input Validation in Universal Link Handlers | iOS | Keep an iOS app's storage, links and web bridge in bounds · LinkTests |
| MASTG-TEST-0394: Missing Input Validation in Custom URL Scheme Handlers | Android | Repair an Android app's links, components, network policy and storage · LinkTests |
Guides on this site
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.
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.
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
List data from the publisher. A guide is listed as the main subject when the weakness or risk is what the guide is about, and as covering it when a dedicated section or worked example addresses it.
Control statements are quoted from OWASP MASVS v2.1.0, licensed CC BY-SA 4.0; the rest is this site's summary. MASTG tests are those the iOS and Android projects here run, with their titles from mas.owasp.org. License.