attack-tree.md

Attack Tree Analysis for facebook/facebook-android-sdk

Objective: Compromise Application Using Facebook Android SDK

Attack Tree Visualization

• Compromise Application Using Facebook Android SDK [CRITICAL NODE]
  • Exploit SDK Vulnerabilities [CRITICAL NODE]
    • Cross-Site Scripting (XSS) in SDK WebViews [CRITICAL NODE] [HIGH-RISK PATH]
      • Inject malicious script via SDK's WebView components
    • Authentication/Authorization Bypass [CRITICAL NODE] [HIGH-RISK PATH]
      • OAuth 2.0 Misconfiguration Exploitation (SDK related) [CRITICAL NODE] [HIGH-RISK PATH]
        • Redirect URI Manipulation (If SDK handles redirect URI poorly) [HIGH-RISK PATH]
          • Intercept or redirect OAuth flow to attacker-controlled site
        • Access Token Theft/Replay (SDK's token handling flaws) [HIGH-RISK PATH]
          • Steal or reuse valid access tokens due to SDK vulnerabilities
    • Vulnerable Dependencies (SDK using vulnerable libraries) [CRITICAL NODE] [HIGH-RISK PATH]
      • Exploit vulnerabilities in SDK's transitive dependencies [HIGH-RISK PATH]
        • Identify and exploit known vulnerabilities in libraries used by the SDK
  • Social Engineering via SDK Features (Indirectly related to SDK flaws, but SDK as a vector) [CRITICAL NODE] [HIGH-RISK PATH]
    • Phishing via Facebook Login Flow (SDK used in phishing) [HIGH-RISK PATH]
      • Manipulate Facebook Login flow initiated by SDK [HIGH-RISK PATH]
        • Present fake Facebook login pages or redirect users to malicious sites via SDK login flows
  • Data Leakage/Information Disclosure
    • Sensitive Data Logging (SDK verbose logging in production) [HIGH-RISK PATH]
      • Extract sensitive user data or tokens from SDK logs

Attack Tree Path: Critical Node: Compromise Application Using Facebook Android SDK

Description: This is the ultimate goal of the attacker. Success means the attacker has gained unauthorized access or control over the application and potentially user data. Risk Level: Critical, as it represents a complete security breach. Mitigation: Implement comprehensive security measures across all areas identified in the attack tree.

Attack Tree Path: Critical Node: Exploit SDK Vulnerabilities

Description: Directly targeting vulnerabilities within the Facebook Android SDK code itself. Successful exploitation bypasses application-level security and leverages weaknesses in a trusted component. Risk Level: Critical, as SDK vulnerabilities can have widespread impact on all applications using the affected SDK version. Mitigation: Keep the SDK updated to the latest version, monitor security advisories, and implement secure coding practices when integrating with the SDK.

Attack Tree Path: High-Risk Path & Critical Node: Cross-Site Scripting (XSS) in SDK WebViews

Attack Vector: Injecting malicious JavaScript code into WebView components used by the SDK. This code can then execute in the context of the application, potentially stealing user data, session tokens, or performing actions on behalf of the user. Vulnerability: Insufficient input sanitization or output encoding when handling data displayed in SDK WebViews. If the SDK uses WebViews to display user-controlled content or external web pages without proper security measures, it becomes vulnerable. Risk Level: High. Likelihood is medium as WebViews are common, impact is medium (data theft, session hijacking), effort is medium, skill level is medium, and detection difficulty is medium. Mitigation: Ensure proper input sanitization and output encoding for all data displayed in WebViews. Implement Content Security Policy (CSP) if possible within the WebView context. Regularly update the SDK and WebView components.

Attack Tree Path: High-Risk Path & Critical Node: Authentication/Authorization Bypass

Description: Circumventing the intended authentication and authorization mechanisms, allowing unauthorized access to application features and user data. Risk Level: Critical, as it directly leads to unauthorized access and potential account takeover. Mitigation: Implement robust authentication and authorization mechanisms, follow OAuth 2.0 best practices, and regularly review and test authentication flows.

Attack Tree Path: High-Risk Path & Critical Node: OAuth 2.0 Misconfiguration Exploitation (SDK related)

Description: Exploiting misconfigurations in the OAuth 2.0 implementation within the SDK or the application's use of it. This is particularly relevant as the Facebook SDK heavily relies on OAuth for authentication and API access. Risk Level: High, as OAuth misconfigurations can lead to account takeover and unauthorized data access. Mitigation: Thoroughly understand and correctly implement OAuth 2.0 flows. Carefully configure redirect URIs, never store client secrets on the client-side, and implement robust token validation.

Attack Tree Path: High-Risk Path: Redirect URI Manipulation (If SDK handles redirect URI poorly)

Attack Vector: Manipulating the redirect URI during the OAuth 2.0 authorization flow. If the SDK or application doesn't properly validate the redirect URI, an attacker can redirect the authorization code or access token to their own controlled server. Vulnerability: Insufficient validation of redirect URIs in the SDK's OAuth implementation or the application's handling of OAuth callbacks. Risk Level: High. Likelihood is medium, impact is high (account takeover), effort is medium, skill level is medium, and detection difficulty is medium. Mitigation: Strictly validate redirect URIs on the server-side. Use allowlists of valid redirect URIs. Ensure the SDK and application follow OAuth 2.0 best practices for redirect URI handling.

Attack Tree Path: High-Risk Path: Access Token Theft/Replay (SDK's token handling flaws)

Attack Vector: Stealing or replaying valid access tokens obtained through the Facebook Login flow. If the SDK has vulnerabilities in how it stores, manages, or transmits access tokens, attackers might be able to intercept or extract them. Replaying a valid token allows unauthorized access without needing to re-authenticate. Vulnerability: Insecure storage of access tokens by the SDK, vulnerabilities in token transmission, or flaws in token validation or revocation mechanisms. Risk Level: High. Likelihood is medium, impact is high (account access), effort is medium, skill level is medium, and detection difficulty is medium. Mitigation: Use secure storage mechanisms for access tokens (e.g., Android Keystore). Ensure tokens are transmitted securely over HTTPS. Implement proper token validation and revocation mechanisms. Regularly update the SDK to patch any token handling vulnerabilities.

Attack Tree Path: High-Risk Path & Critical Node: Vulnerable Dependencies (SDK using vulnerable libraries)

Description: The Facebook Android SDK, like most software, relies on third-party libraries (dependencies). If these dependencies have known vulnerabilities, they can be exploited through the SDK, even if the SDK code itself is secure. Risk Level: Critical, as vulnerable dependencies are a common attack vector and can have a wide range of impacts, including Remote Code Execution (RCE) and Data Breach. Mitigation: Regularly scan the application and SDK dependencies for known vulnerabilities using dependency checking tools. Update dependencies to patched versions promptly. Implement a Software Bill of Materials (SBOM) to track dependencies.

Attack Tree Path: High-Risk Path: Exploit vulnerabilities in SDK's transitive dependencies

Attack Vector: Exploiting known vulnerabilities in the transitive dependencies of the Facebook Android SDK. Transitive dependencies are libraries that the SDK's direct dependencies rely on. Vulnerabilities in these can be less obvious but equally exploitable. Vulnerability: Known security vulnerabilities in any of the libraries (direct or transitive) used by the Facebook Android SDK. Risk Level: High. Likelihood is medium (common dependency vulnerabilities), impact is high (wide range), effort is low (for known exploits), skill level is low (for known exploits), and detection difficulty is medium (dependency scanning tools can detect). Mitigation: Maintain an up-to-date inventory of all dependencies (including transitive). Use automated dependency scanning tools to identify vulnerabilities. Prioritize updating vulnerable dependencies, especially those with known exploits.

Attack Tree Path: High-Risk Path & Critical Node: Social Engineering via SDK Features (Indirectly related to SDK flaws)

Description: Abusing features of the Facebook SDK, particularly login and sharing functionalities, to conduct social engineering attacks like phishing. While not a direct SDK vulnerability in code, the SDK provides the tools that can be misused. Risk Level: High, as social engineering attacks can be very effective, especially on mobile platforms, and can lead to credential theft and account takeover. Mitigation: Educate users about phishing attacks and how to recognize fake login pages. Implement UI/UX best practices to make login flows transparent and secure. Implement content validation for sharing features to prevent malicious content propagation.

Attack Tree Path: High-Risk Path: Phishing via Facebook Login Flow (SDK used in phishing)

Attack Vector: Creating fake login pages that mimic the Facebook Login flow initiated by the SDK. Attackers can present these fake pages to users, tricking them into entering their Facebook credentials, which are then stolen. Vulnerability: User susceptibility to phishing attacks, especially on mobile where URLs might be less visible. The SDK's login flow, if not carefully implemented in the UI, can be mimicked. Risk Level: High. Likelihood is medium (users can be tricked), impact is high (credential theft, account takeover), effort is low, skill level is low, and detection difficulty is low (user education is key). Mitigation: Educate users about phishing risks and how to identify fake login pages. Use browser-based login flows where the URL is clearly visible. Implement UI/UX best practices to make the login flow as secure and transparent as possible.

Attack Tree Path: High-Risk Path: Manipulate Facebook Login flow initiated by SDK

Attack Vector: Specifically manipulating the login flow initiated by the SDK to present a fake login interface or redirect users to malicious websites after (or even before) the legitimate Facebook login process. Vulnerability: Application's UI implementation of the login flow might be susceptible to manipulation, or users might not be sufficiently aware of the legitimate Facebook login interface. Risk Level: High. Likelihood is medium, impact is high (credential theft, account takeover), effort is low, skill level is low, and detection difficulty is low (user education is key). Mitigation: Ensure the login flow UI is robust and difficult to mimic. Clearly indicate that the login is happening through the official Facebook platform (e.g., by showing the facebook.com URL in a browser-based flow). Educate users to be cautious and verify the legitimacy of login pages.

Attack Tree Path: High-Risk Path: Sensitive Data Logging (SDK verbose logging in production)

Attack Vector: The SDK or the application might inadvertently log sensitive data (like access tokens, user IDs, API keys) in production logs. If these logs are accessible to attackers (e.g., through insecure storage, log aggregation services, or device access), the sensitive data can be compromised. Vulnerability: Verbose logging configurations in production, insecure storage or access control for logs, or unintentional logging of sensitive information by the SDK or application code. Risk Level: High. Likelihood is medium (if default logging is verbose), impact is medium (data exposure), effort is low (if logs are easily accessible), skill level is low, and detection difficulty is low (logs are usually visible). Mitigation: Disable verbose logging in production builds. If logging is necessary, ensure sensitive data is not logged or is properly anonymized/masked. Securely store and manage application logs, implementing strict access controls. Regularly review logging configurations and practices.