threat-modeling.md

Threat Model Analysis for nst/ios-runtime-headers

Threat: Private API Functionality Disruption Leading to Application Failure

• Description: ios-runtime-headers provides access to private iOS APIs. Apple can change or remove these private APIs in any iOS update without notice. If an application relies on these APIs (exposed through ios-runtime-headers), an iOS update can directly break the application's functionality, leading to crashes or critical feature failures. The attacker here is not a malicious actor, but rather the inherent instability of relying on private APIs exposed by ios-runtime-headers when iOS is updated.
• Impact: Application becomes unusable or critically flawed after iOS updates, loss of core functionality, negative user experience, application store rejection due to broken functionality after OS updates.
• Affected Component: Application modules and functions that utilize any private API header provided by ios-runtime-headers.
• Risk Severity: High
• Mitigation Strategies:
  • Drastically reduce or eliminate the use of private APIs accessed via ios-runtime-headers. Prioritize public, documented APIs.
  • Implement robust feature detection and fallback mechanisms. If a private API (defined by ios-runtime-headers) is unavailable or behaves differently after an iOS update, the application should gracefully degrade functionality or use alternative public APIs.
  • Establish a rigorous testing process on every iOS beta release. Specifically test all features relying on private APIs (exposed by ios-runtime-headers) to identify and address breakages before public iOS release.
  • Design application architecture to minimize dependencies on private APIs. Isolate private API usage to specific modules to contain the impact of potential breakages.

Threat: Memory Corruption Vulnerabilities from Incorrect Private API Calls

• Description: Due to the lack of official documentation for private APIs (accessed via ios-runtime-headers), developers may misuse them. Incorrectly calling private APIs, especially those dealing with memory management (exposed by ios-runtime-headers), can introduce critical memory corruption vulnerabilities such as buffer overflows, use-after-free, or double-free. An attacker could exploit these vulnerabilities by crafting specific inputs or triggering application flows that interact with the flawed private API calls, potentially leading to arbitrary code execution. The vulnerability is directly introduced by the incorrect usage of APIs made accessible by ios-runtime-headers.
• Impact: Arbitrary code execution, application takeover, data breaches, denial of service, complete compromise of the application and potentially the user's device.
• Affected Component: Specific functions and methods within the application that directly call private APIs defined in ios-runtime-headers, particularly memory management related APIs.
• Risk Severity: Critical
• Mitigation Strategies:
  • Extensive and meticulous code review of all code paths using private APIs from ios-runtime-headers. Focus on memory management, pointer handling, and data type conversions.
  • Mandatory static analysis and dynamic analysis (including fuzzing) specifically targeting code interacting with private APIs from ios-runtime-headers. Use tools to detect memory errors and potential vulnerabilities.
  • Implement strict input validation and sanitization for all data passed to private APIs obtained through ios-runtime-headers. Assume private APIs are highly sensitive to unexpected input.
  • Utilize memory safety tools and languages features where possible. Consider using safer memory management techniques and languages for components interacting with private APIs (though this might be limited in iOS development).
  • Isolate and sandbox code sections that use private APIs from ios-runtime-headers as much as possible. Limit the potential damage if a vulnerability is exploited in these sections.

Threat: Information Disclosure of Sensitive Data via Private APIs

• Description: Private APIs (accessed through ios-runtime-headers) might expose internal system data or application-sensitive information not intended for public access. If developers unknowingly or carelessly log, transmit, or display this data, it can lead to critical information disclosure. An attacker could potentially intercept network traffic, analyze application logs (if accessible), or exploit other vulnerabilities to gain access to this leaked sensitive information obtained from private APIs exposed by ios-runtime-headers. The risk is directly tied to the data exposed by private APIs made accessible by ios-runtime-headers.
• Impact: Disclosure of sensitive user data (credentials, personal information), internal application secrets, security keys, or information about system internals that could aid further attacks or compromise user privacy and security.
• Affected Component: Code sections that process, log, transmit, or display data retrieved from private APIs defined in ios-runtime-headers, especially logging frameworks, network communication modules, and UI display components.
• Risk Severity: High
• Mitigation Strategies:
  • Thoroughly analyze the data returned by all private APIs used from ios-runtime-headers to understand its nature and sensitivity. Treat all data from private APIs as potentially sensitive by default.
  • Implement strict data sanitization, filtering, and redaction for any data originating from private APIs (exposed by ios-runtime-headers) before logging, transmission, or display.
  • Avoid logging detailed information about private API interactions in production environments. If logging is necessary, ensure sensitive data is explicitly excluded.
  • Enforce secure coding practices and data handling policies specifically for data obtained from private APIs accessed via ios-runtime-headers.
  • Regularly audit application logs, network traffic, and data handling procedures for potential unintended information leaks originating from private API usage.