Skip to content

Latest commit

 

History

History
99 lines (74 loc) · 9.79 KB

mitigations.md

File metadata and controls

99 lines (74 loc) · 9.79 KB

Mitigation Strategies Analysis for oracle/graal

Mitigation Strategy: Rigorous Reflection Configuration via Tracing Agent

  • Description:

    1. Integrate the Tracing Agent: Add the -agentlib:native-image-agent=config-output-dir=<output-directory> option to your application's JVM startup command during development and testing. <output-directory> should be a dedicated directory for the agent's output.
    2. Run Comprehensive Tests: Execute a wide range of tests (unit, integration, end-to-end) while the tracing agent is active. Ensure all code paths that use reflection, JNI, resources, or dynamic proxies are exercised.
    3. Collect Configuration Files: The agent will generate JSON files (reflect-config.json, resource-config.json, jni-config.json, proxy-config.json, serialization-config.json) in the specified output directory.
    4. Refine Configuration: Review the generated configuration files. Remove unnecessary entries. Be as specific as possible, listing only the classes, methods, fields, and resources that must be accessible. Avoid wildcard entries or overly permissive settings ("allowAll": true).
    5. Integrate into Build: Add the -H:ConfigurationFileDirectories=<output-directory> option to your native-image build command, pointing to the directory containing the refined configuration files.
    6. Regular Updates: Repeat steps 1-5 whenever your application's code changes, especially if those changes involve reflection, JNI, resources, or dynamic proxies. Integrate this into your CI/CD pipeline.

  • Threats Mitigated:

    • Arbitrary Code Execution via Reflection (Severity: High): Attackers could use reflection to instantiate arbitrary classes and invoke methods, potentially leading to complete system compromise.
    • Unauthorized Resource Access (Severity: Medium): Attackers could access sensitive resources (configuration files, data) not intended to be exposed.
    • JNI Exploitation (Severity: High): Vulnerabilities in native code accessed via JNI can bypass Java security.
    • Dynamic Proxy Manipulation (Severity: Medium): Attackers could interfere with the behavior of dynamic proxies.
    • Serialization/Deserialization Attacks (Severity: High): Uncontrolled deserialization of untrusted data can lead to arbitrary code execution.

  • Impact:

    • Arbitrary Code Execution via Reflection: Risk significantly reduced (High to Low/Medium).
    • Unauthorized Resource Access: Risk significantly reduced (Medium to Low).
    • JNI Exploitation: Risk reduced (mitigates discovery of JNI entry points, but not vulnerabilities within the native code). Severity remains High if native code is vulnerable.
    • Dynamic Proxy Manipulation: Risk reduced (Medium to Low).
    • Serialization/Deserialization Attacks: Risk significantly reduced (High to Low/Medium).

  • Currently Implemented: Partially. Tracing agent is used during development, but configuration files are not regularly updated and are not integrated into the CI/CD pipeline. Configuration is not as specific as it could be.

  • Missing Implementation: Automated regeneration of configuration files in CI/CD. Refinement of configuration files to be more specific. Regular review of configuration files.

Mitigation Strategy: Minimize and Secure Polyglot Interactions

  • Description:

    1. Context Isolation: Create separate Context instances for different guest languages or modules, even if they need to interact.
    2. Restrict Host Access: When creating a Context, use the most restrictive settings possible:
      • allowAllAccess(false)
      • allowHostAccess(HostAccess.NONE) (or a very specific HostAccess configuration built with HostAccess.newBuilder())
      • allowIO(false)
      • allowCreateThread(false)
      • allowHostClassLookup with a strict predicate that only allows access to specific, necessary classes.
      • allowHostSymbolAccess only if absolutely necessary and with careful consideration.
    3. Data Sanitization: Implement strict input validation and sanitization for all data passed between languages. Treat data from other languages as untrusted. Validate data types, lengths, and contents.
    4. Controlled Communication: If different Context instances need to communicate, use explicit and secure mechanisms like shared memory (with appropriate synchronization) or message queues, rather than relying on direct access through the polyglot API.
    5. Regular Updates: Keep all guest language implementations up to date.

  • Threats Mitigated:

    • Cross-Language Code Injection (Severity: High): An attacker could inject malicious code in one language (e.g., JavaScript) that executes in another (e.g., Java), bypassing security.
    • Unauthorized Host Access (Severity: High): A guest language could gain unauthorized access to Java classes, methods, and resources.
    • Guest Language Vulnerabilities (Severity: Medium/High): Vulnerabilities in a guest language implementation could be exploited.
    • Data Tampering (Severity: Medium): Data passed between languages could be modified.

  • Impact:

    • Cross-Language Code Injection: Risk significantly reduced (High to Low/Medium).
    • Unauthorized Host Access: Risk significantly reduced (High to Low).
    • Guest Language Vulnerabilities: Risk reduced (mitigates the impact by limiting access). Severity remains dependent on the specific guest language.
    • Data Tampering: Risk significantly reduced (Medium to Low).

  • Currently Implemented: Partially. HostAccess is restricted, but not to the most restrictive level. Data sanitization is not consistently applied. Separate Contexts are not always used.

  • Missing Implementation: Consistent use of separate Context instances. Stricter HostAccess configurations. Comprehensive data sanitization for all inter-language communication. Regular updates of guest language implementations are not automated.

Mitigation Strategy: Secure Serialization Alternatives (with GraalVM Configuration)

  • Description:

    1. Avoid Java Serialization: Prefer JSON (Jackson, Gson) or Protocol Buffers.
    2. GraalVM Configuration: If using a library like Jackson, ensure it's properly configured for Native Image. This often involves providing metadata about the classes to be serialized/deserialized. Use the tracing agent to help identify these classes and generate the necessary configuration files.
    3. Data Validation: Thoroughly validate all deserialized data, regardless of the mechanism.
    4. Last Resort: Custom ObjectInputStream (with Tracing Agent): If Java serialization must be used, implement a custom ObjectInputStream that overrides resolveClass. In resolveClass, check if the class is on an explicit allowlist. Reject any class not on the allowlist. Use the tracing agent to generate the initial allowlist.

  • Threats Mitigated:

    • Deserialization Attacks (Severity: High): Uncontrolled deserialization of untrusted data can lead to arbitrary code execution.

  • Impact:

    • Deserialization Attacks: Risk significantly reduced (High to Low if alternatives are used; High to Medium if a custom ObjectInputStream is used).

  • Currently Implemented: Partially. JSON serialization is used in some parts, but Java serialization is still present. No custom ObjectInputStream.

  • Missing Implementation: Complete migration away from Java serialization. Implementation of a custom ObjectInputStream as a fallback. Consistent data validation after deserialization. Proper GraalVM configuration for the chosen serialization library (using the tracing agent).

Mitigation Strategy: Native Image Dependency Compatibility Checks (using the Tracing Agent)

  • Description:

    1. Dependency Analysis: Before adding a new dependency, use the native-image-agent in a test environment with the new dependency included.
    2. Configuration Generation: Run your application with the tracing agent and a representative set of tests. The agent will generate configuration files that reflect the dependency's use of reflection, JNI, resources, etc.
    3. Compatibility Assessment: Examine the generated configuration files. Large or complex configuration files may indicate potential compatibility issues or a larger attack surface.
    4. Iterative Refinement: If issues are found, try to find alternative dependencies or work with the library maintainers to improve Native Image compatibility.

  • Threats Mitigated:

    • Native Image Incompatibility (Severity: Medium): Some dependencies may not work correctly with Native Image, leading to runtime errors or unexpected behavior.
    • Indirect Reflection/JNI Usage (Severity: Medium/High): Dependencies might use reflection or JNI internally, which needs to be properly configured for Native Image. This helps uncover those hidden uses.

  • Impact:

    • Native Image Incompatibility: Risk reduced (proactive checking helps prevent integration of incompatible dependencies).
    • Indirect Reflection/JNI Usage: Risk reduced by identifying and configuring these usages.

  • Currently Implemented: Not implemented.

  • Missing Implementation: Implementation of a process to use the tracing agent to check new dependencies for Native Image compatibility before they are integrated into the main codebase.