AppEnumGuard

AppEnumGuard is a defensive rootHide tweak for the installed-application enumeration side channel tracked as CVE-2025-31207. It is designed for the Relaxin jailbreak on iOS 17.0–17.3.1, using Relaxin's rootHide architecture. The repository also contains a normal sandboxed iOS test application that demonstrates the vulnerable result and verifies the mitigation.

CVE-2025-31207

CVE-2025-31207 is an information-disclosure vulnerability in Apple's FrontBoard application-launching logic. A sandboxed application can submit arbitrary bundle identifiers through a private SpringBoardServices launch function and distinguish installed applications from missing applications using different return codes. This can reveal private information about the applications a user has installed, including banking, messaging, security, sideloading, and jailbreak-related apps.

Apple describes the issue as a logic problem that could let an application enumerate installed apps. Apple corrected it with improved checks in iOS and iPadOS 18.5. Consequently, iOS 17.0–17.3.1 remains affected at the OS level.

Compatibility

Relaxin uses the rootHide bootstrap/package architecture, so AppEnumGuard is built with rootHide Theos and contains rootHide .jbroot loader paths. The package declares firmware (>= 17.0) and firmware (<< 17.4), matching the supported Relaxin range of 17.0–17.3.1.

The tweak and tester were verified together on a real Relaxin/rootHide device: the tester detected the leak with the tweak removed and returned a green pass after the tweak was installed.

How it works

The published primitive calls the private SpringBoardServices function SBSLaunchApplicationWithIdentifierAndURLAndLaunchOptions. On a vulnerable system it returns different errors for an installed application and a missing application:

• 9: target exists, but launch is denied by policy
• 7: target does not exist

The tweak is injected into UIKit application processes. For an ordinary container-installed application, it returns 7 without submitting the private launch request. Apple and other system processes outside the application container retain the original behavior.

Release downloads

Each GitHub release contains both installable artifacts:

• AppEnumGuard_1.0.0_roothide_iphoneos-arm64e.deb — rootHide tweak
• AppEnumGuardTester_1.0.0_sandboxed.ipa — sandboxed verification app

Install and verify

1. Install the rootHide .deb and respring.
2. Install the tester IPA using a normal developer/sideloading signature.
3. Ensure tweak injection is enabled for AppEnum Test.
4. Install WhatsApp, or enter the bundle identifier of another known installed application.
5. Tap Run comparison.

Expected results with WhatsApp installed:

The original device test reproduced both states: uninstalling the tweak produced the red 9 / 7 result, while installing it produced the green 7 / 7 result.

Build the tweak

Install rootHide Theos, then run:

cd Tweak
THEOS=/path/to/theos-roothide \
  make clean package FINALPACKAGE=1 THEOS_PACKAGE_SCHEME=roothide

Build the tester IPA

The tester is compiled with Xcode's iPhoneOS SDK and has no jailbreak or elevated entitlements:

./scripts/build-tester-ipa.sh

The resulting IPA is placed in dist/. It is ad-hoc signed so an installer may re-sign it with a normal development identity. Do not grant it platform-application or com.apple.private.security.no-sandbox, since the test is specifically intended to run from a normal application sandbox.

Scope and limitations

• This is a user-space mitigation for the published SpringBoardServices primitive, not Apple's complete FrontBoard patch.
• An application that disables tweak injection cannot be protected by a client-side injected tweak.
• A 7 / 7 test is meaningful only when the target application is known to be installed.
• The tester intentionally calls an undocumented private API and is not suitable for App Store submission.

References

• Apple iOS 18.5 security content
• NVD: CVE-2025-31207
• Original public SpringBoardServices proof of concept
• rootHide developer documentation

License

MIT