How to Detect Cydia iOS Jailbreak, Protect iOS Apps

Last updated December 6, 2023 by Appdome

Learn to Detect Jailbreak in iOS apps, in mobile CI/CD with a Data-Driven DevSecOps™ build system.

What is Cydia?

Cydia is an alternative app store that allows mobile end users to find and install software not authorized by Apple on jailbroken iPhones, iPads and iPod touch devices. It also refers to the digital distribution platform for software on iOS accessed through Cydia software. Downloading Cydia requires jailbreaking the iOS-based device, thus allowing users to escalate privileges in order to obtain access to, and modify, the iOS File System.

How Does Appdome Detect Cydia in iOS Apps?

As an integral part of Jailbreak Detection protection, Appdome blocks various utilities widely used by hackers to perform jailbreaking, including Cydia. In so doing Appdome allows users to avoid all security risk involved in jailbreaking, an operation that seriously compromises the mobile security model. Any iOS app that runs on a Jailbroken device is in a vulnerable state, where hackers can amplify and increase the magnitude of their attacks.

Any malicious actor who succeeds in jailbreaking an iOS-based device will find it much easier to disable anti-tampering protections as well as security protections, to modify the iOS file system, to change properties files, and to modify the device’s behavior in general. When iOS apps run on Jailbroken devices you really cannot trust any of the signals, messages, or behaviors associated with the device (or anything running on the device).

Prerequisites for Using Jailbreak Detection:

To use Appdome’s mobile app security build system to Detect Jailbreak , you’ll need:

Detect Jailbreak on iOS apps using Appdome

On Appdome, follow these 3 simple steps to create self-defending iOS Apps that Detect Jailbreak without an SDK or gateway:

  1. Upload the Mobile App to Appdome.

    1. Upload an app to Appdome’s Mobile App Security Build System

    2. Upload Method: Appdome Console or DEV-API
    3. iOS Formats: .ipa
    4. Jailbreak Detection Compatible With: Obj-C, C+, Java, Swift, Flutter, React Native, Unity, Xamarin, Cordova and more
  2. Build the feature: Jailbreak Detection.

    1. Building Jailbreak Detection by using Appdome’s DEV-API:

      1. Create and name the Fusion Set (security template) that will contain the Jailbreak Detection feature as shown below:
      2. fusion set that contains Jailbreak Detection

        Figure 1: Fusion Set that will contain the Jailbreak Detection feature
        Note: Naming the Fusion Set to correspond to the protection(s) selected is for illustration purposes only (not required).

      3. Follow the steps in Sections 2.2.1-2.2.2 of this article, Building the Jailbreak Detection feature via Appdome Console, to add the Jailbreak Detection feature to this Fusion Set.

      4. Open the Fusion Set Detail Summary by clicking the “...” symbol on the far-right corner of the Fusion Set, as shown in Figure 1 above, and get the Fusion Set ID from the Fusion Set Detail Summary (as shown below): fusion Set Detail Summary image

        Figure 2: Fusion Set Detail Summary
        Note: Annotating the Fusion Set to identify the protection(s) selected is optional only (not mandatory).

      5. Follow the instructions below to use the Fusion Set ID inside any standard mobile DevOps or CI/CD toolkit like Bitrise, App Center, Jenkins, Travis, Team City, Cirlce CI or other system:
        1. Build an API for the app – for instructions, see the tasks under Appdome API Reference Guide
        2. Look for sample APIs in Appdome’s GitHub Repository
    2. Building the Jailbreak Detection feature via Appdome Console

      To build the Jailbreak Detection protection by using Appdome Console, follow the instructions below.

      1. Where: Inside the Appdome Console, go to Build > Security Tab > OS Integrity section
      2. How: Toggle (turn ON) Jailbreak Detection, as shown below.
        If needed, Customize the Threat Notification to be displayed to the mobile end-user in a standard OS dialog notification when Appdome Detects Jailbreak. Jailbreak Detection option

        Figure 3: Detect Jailbreak option
        Note: The App Compromise Notification contains an easy to follow default remediation path for the mobile app end user. You can customize this message as required to achieve brand specific support, workflow or other messaging.

      3. When you select the Jailbreak Detection you'll notice that your Fusion Set you created in step 2.1.1 now bears the icon of the protection category that contains Jailbreak Detection

        Fusion Set applied Jailbreak Detection

        Figure 4: Fusion Set that displays the newly added Jailbreak Detection protection

      4. Select the Threat-Event™ in-app mobile Threat Defense and Intelligence policy for Jailbreak Detection:
        1. Threat-Events™ OFF > In-App Defense

          If the Threat-Events™ setting is cleared (not selected). Appdome will detect and defend the user and app by enforcing Detect Jailbreak.

        2. Threat-Events™ ON > In-App Detection

          When this setting is used, Appdome detects that the app is running on a Jailbroken device and using Cydia and passes Appdome’s Threat-Event™ attack intelligence to the app’s business logic for processing, enforcement, and user notification. For more information on consuming and using Appdome Threat-Events™ in the app, see section Using Threat-Events™ for Jailbreak Detection Intelligence and Control in Mobile Apps.

        3. Threat-Events™ ON > In-App Defense

          When this setting is used, Appdome detects and defends against Jailbreak (same as Appdome Enforce) and passes Appdome’s Threat-Event™ attack intelligence the app’s business logic for processing. For more information on consuming and using Appdome Threat-Events™ in the app, see section Using Threat-Events™ for Jailbreak Detection Intelligence and Control in Mobile Apps.

      5. Click Build My App at the bottom of the Build Workflow (shown in Figure 3).
    Congratulations!  The Jailbreak Detection protection is now added to the mobile app
  3. Certify the Jailbreak Detection feature in iOS Apps.

    After building Jailbreak Detection, Appdome generates a Certified Secure™ certificate to guarantee that the Jailbreak Detection protection has been added and is protecting the app. To verify that the Jailbreak Detection protection has been added to the mobile app, locate the protection in the Certified Secure™ certificate as shown below: Jailbreak Detection shown in Certificate secure

    Figure 5: Certified Secure™ certificate

    Each Certified Secure™ certificate provides DevOps and DevSecOps organizations the entire workflow summary, audit trail of each build, and proof of protection that Jailbreak Detection has been added to each iOS app. Certified Secure provides instant and in-line DevSecOps compliance certification that Jailbreak Detection and other mobile app security features are in each build of the mobile app

Using Threat-Events™ for Jailbreak Intelligence and Control in iOS Apps

Appdome Threat-Events™ provides consumable in-app mobile app attack intelligence and defense control when Jailbreak is detected. To consume and use Threat-Events™ for Jailbreak in iOS Apps, use AddObserverForName in Notification Center, and the code samples for Threat-Events™ for Jailbreak shown below.

The specifications and options for Threat-Events™ for Jailbreak are:

Threat-Event™ Elements Detect Jailbreak Method Detail
Appdome Feature Name Jailbreak Detection
Threat-Event Mode
OFF, IN-APP DEFENSE Appdome detects, defends and notifies user (standard OS dialog) using customizable messaging.
ON, IN-APP DETECTION Appdome detects the attack or threat and passes the event in a standard format to the app for processing (app chooses how and when to enforce).
ON, IN-APP DEFENSE Uses Appdome Enforce mode for any attack or threat and passes the event in a standard format to the app for processing (gather intel on attacks and threats without losing any protection).
Certified Secure™ Threat Event Check
Visible in ThreatScope™
Developer Parameters for Detecting Jailbreak Threat-Event™
Threat-Event NAME JailbrokenDevice
Threat-Event DATA reasonData
Threat-Event CODE reasonCode
Threat-Event REF 6801
Threat-Event SCORE
currentThreatEventScore Current Threat-Event score
threatEventsScore Total Threat-events score
Threat-Event Context Keys
message Message displayed for the user on event
externalID The external ID of the event which can be listened via Threat Events
osVersion OS version of the current device
deviceModel Current device model
deviceManufacturer The manufacturer of the current device
fusedAppToken The task ID of the Appdome fusion of the currently running app
kernelInfo Info about the kernel: system name, node name, release, version and machine.
carrierPlmn PLMN of the device
deviceID Current device ID
reasonCode Reason code of the occured event
buildDate Appdome fusion date of the current application
devicePlatform OS name of the current device
carrierName Carrier name of the current device
updatedOSVersion Is the OS version up to date
timeZone Time zone
deviceFaceDown Is the device face down
locationLong Location long
locationLat Location lat
locationState Location state
wifiSsid Wifi SSID
wifiSsidPermissionStatus Wifi SSID permission status
internalError Internal error code as hex
extendedMessageText Internal error code
rInternalErrorCode Internal error code
reason Reason for the root detection

With Threat-Events™ enabled (turned ON), iOS developers can get detailed attack intelligence and granular defense control in iOS applications and create amazing user experiences for all mobile end users when Jailbreak is detected.

The following is a code sample for native iOS apps, which uses all values in the specification above for Jailbreak Detection:


Using Appdome, there are no development or coding prerequisites to build secured iOS Apps by using Jailbreak Detection. There is no SDK and no library to code or implement in the app and no gateway to deploy in your network. All protections are built into each app and the resulting app is self-defending and self-protecting.

Releasing and Publishing Mobile Apps with Jailbreak Detection

After successfully securing your app by using Appdome, there are several available options to complete your project, depending on your app lifecycle or workflow. These include:

Related Articles:

Here are some KB articles related to Cydia and iOS Jailbreaking:

If you have any questions, please send them our way at support.appdome.com or via the chat window on the Appdome platform.

Thank you!

Thanks for visiting Appdome! Our mission is to secure every app on the planet by making mobile app security easy. We hope we’re living up to the mission with your project.

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