Deep Dive into Info.plist Security Flags for Penetration Testing

When performing penetration tests or static analysis on iOS/macOS applications, one of the most overlooked but critical files is Info.plist. This file contains configuration keys that control behavior, privacy permissions, app transport security, input handling, and much more.

Many of these settings can unintentionally expose sensitive data, allow insecure communications, or increase the attack surface of an app. This article provides a detailed analysis of common Info.plist keys, explains their technical behavior, illustrates real-world abuse cases, and offers security best practices for each.

🔧 Debugging & Security Flags

Key	Technical Description	Usage in Development	Security Risk	Real-World Example	Best Practice
`UIFileSharingEnabled`	Boolean (`false` by default). If `true`, exposes the app’s `Documents/` directory to iTunes/Finder file sharing.	Apps that allow file import/export (e.g. document editors).	Attackers with physical access can extract SQLite databases, tokens, and logs stored in `Documents/`.	Productivity apps exposed sensitive files via this flag in earlier iOS versions.	Set to `false` for production; move sensitive data to `Library/Private`.
`LSSupportsOpeningDocumentsInPlace`	Allows editing files from external sources like iCloud without copying into the sandbox.	Used by code editors, drawing tools.	Malicious apps can overwrite or tamper with files through symbolic links or sandbox escapes.	Exploits have overwritten "in-place" Realm DB files to cause corruption or injection.	Use security-scoped bookmarks and validate file access repeatedly.
`UIApplicationExitsOnSuspend`	When `true`, the app terminates when backgrounded. Prevents lingering memory data.	Used by banking or password vaults to increase memory security.	If `false`, sensitive keys/tokens may stay in memory until system purges the app.	Trading apps leaked access tokens in suspended state.	Enable if the UX permits and wipe memory on background transition.
`UIBackgroundModes`	Allows specific background capabilities: `audio`, `fetch`, `location`, etc.	Messaging, music, or GPS apps.	Overused modes (like `location`) enable data exfiltration and power analysis attacks.	Citizen Lab reported spyware using `location` + `bluetooth-central` for passive surveillance.	Declare only necessary modes and monitor task lifetimes.
`ITSAppUsesNonExemptEncryption`	Indicates use of strong encryption (for export compliance).	Games or simple apps might set `false`.	Setting `false` while using TLS violates compliance (e.g. GDPR, PCI).	US lottery apps were delisted after audit revealed encrypted traffic but `false` flag.	Always set to `true` when using TLS, AES, or RSA.
`UIApplicationSupportsIndirectInputEvents`	Enables input from external devices like braille or USB keyboards.	Accessibility or point-of-sale apps.	Allows injection or keylogging via HID spoofing.	Black Hat 2021 showed USB devices injecting malicious sequences.	Only enable if needed and whitelist HID inputs.

🌐 Network & Data Security Flags

Key	Technical Description	Usage in Development	Security Risk	Real-World Example	Best Practice
`NSAllowsArbitraryLoads`	Disables ATS (App Transport Security) and allows insecure HTTP.	Used during HTTP-to-HTTPS migration.	Enables MITM attacks, downgrades, and data leakage.	Banking apps leaked analytics data over HTTP due to this setting.	Always `false`; use `NSExceptionDomains` for granular exceptions.
`NSExceptionDomains`	Specifies per-domain ATS exceptions like cipher suite or TLS version.	Whitelist legacy servers.	Wildcards (`NSIncludesSubdomains=true`) expose QA/staging to attack.	QA environments exposed via CDN wildcard subdomains.	Define exact hostnames and monitor for abuse.
`NSAllowsLocalNetworking`	Allows connections to `.local` or Bonjour services without TLS.	IoT configuration apps (e.g. smart devices).	App can scan internal network, pivot, or exploit devices.	PoC app extracted default credentials from IP cams on LAN.	Validate Bonjour targets and restrict protocols.
`NSAppTransportSecurity`	Master dictionary that controls ATS settings.	Required for modern iOS apps.	Weak or incomplete settings (e.g. RC4 cipher allowed) reduce security posture.	MOBIX identified apps allowing insecure TLS versions.	Enforce TLS 1.2+, perfect forward secrecy, and CT.
`NSContactsUsageDescription`	Custom prompt when accessing user contacts.	Social apps or calendars.	Poor justification leads to over-permission; can aid phishing or spam.	Casual games uploaded contact lists to ad brokers.	Use clear messages and encrypt data at rest.

🔒 Privacy & Data Exposure Risks

Key	Technical Description	Usage in Development	Security Risk	Real-World Example	Best Practice
`NSCameraUsageDescription`	Prompt shown when using the camera.	Document scanners, AR apps.	Can enable covert surveillance without feedback.	Zoom macOS bug kept camera active post-call.	Show visual indicators and pause when backgrounded.
`NSMicrophoneUsageDescription`	Prompt for microphone access.	VoIP or recording apps.	Eavesdropping or background recording.	Pegasus malware used microphone access post-jailbreak.	Disable session when inactive.
`NSPhotoLibraryUsageDescription`	Allows access to the user’s photo library.	Editors, uploaders, social media.	EXIF GPS metadata can reveal sensitive locations.	Ad SDKs used image hashes for fingerprinting.	Use `PHPickerViewController` to limit scope.
`NSLocationAlwaysUsageDescription`	Enables tracking even when the app is closed.	Navigation, delivery apps.	Tracking across time and space violates user expectations.	Data brokers bought GPS data from health-related apps.	Prefer `WhenInUse`; provide toggles for users.
`NSUserTrackingUsageDescription`	Required by AppTrackingTransparency (ATT) to access IDFA.	Ad monetization.	Apps that fingerprint users after denial violate ATT/GDPR.	Adjust SDK was rejected by Apple for ATT circumvention.	Only use when critical for ad revenue.

⚙️ App Execution & IPC Risks

Key	Technical Description	Usage in Development	Security Risk	Real-World Example	Best Practice
`CFBundleURLTypes` (Deep Linking)	Registers custom URL schemes (`myapp://`).	Password reset flows, login deep links.	Other apps can hijack and invoke these URLs with malicious input.	Health apps vulnerable to OAuth token theft via deep link hijacking.	Use `Universal Links` with HTTPS and signed association.
`CFBundleExecutable`	Defines the binary name.	Apps using multiple binaries.	Tampering attacks can replace the binary post-install.	Masque Attack (2014) exploited bundle executable swaps.	Validate executable hash in runtime.
`CFBundleIdentifier`	App’s unique reverse-DNS ID.	Build separation (prod, QA).	Identifier collisions allow data theft via malicious apps.	Masque Attack cloned bundle ID to extract Keychain data.	Only install from trusted sources; enforce code signing.
`UIRequiresFullScreen`	Forces full-screen mode.	Games and immersive apps.	Hides status bar or security indicators like mic/camera usage.	Lottery apps hid indicators using fullscreen overlays.	Allow multitasking unless UX absolutely requires fullscreen.
`LSApplicationQueriesSchemes`	Allows checking if other apps are installed.	Deep link logic or conditional flows.	Overuse creates fingerprinting vectors.	Some apps queried 50+ schemes for tracking.	Limit to critical schemes only.

✅ Final Thoughts

These Info.plist keys, while often viewed as just metadata, can have a massive impact on an app’s security posture. Static analysis of the Info.plist is a key part of mobile pentesting, jailbreak bypass detection, and compliance validation.