Skip to content

Latest commit

 

History

History
28 lines (23 loc) · 3.3 KB

attack-surface.md

File metadata and controls

28 lines (23 loc) · 3.3 KB

Attack Surface Analysis for apache/commons-lang

Attack Surface: Deserialization of Untrusted Data

  • Description: Deserialization vulnerabilities occur when an application deserializes data from an untrusted source without proper validation, allowing an attacker to inject malicious objects that can execute arbitrary code.
  • Commons Lang Contribution: SerializationUtils.deserialize() and SerializationUtils.clone() provide the mechanism for deserialization, making it easy to implement but also easy to misuse. These methods are the direct enablers of this vulnerability.
  • Example: An attacker sends a crafted serialized object as part of a request parameter. The application uses SerializationUtils.deserialize() to process this parameter without validating its source or contents. The injected object contains a malicious readObject() method that executes a shell command.
  • Impact: Remote Code Execution (RCE), complete system compromise.
  • Risk Severity: Critical
  • Mitigation Strategies:
    • Avoid Untrusted Deserialization: The primary mitigation is to never deserialize data from untrusted sources.
    • Whitelist-Based Deserialization: If deserialization of untrusted data is absolutely unavoidable, use a secure deserialization framework with a strict whitelist of allowed classes. Do not rely solely on Commons Lang.
    • ClassLoaderObjectInputStream with Whitelist: If using SerializationUtils, employ a custom ObjectInputStream (like ClassLoaderObjectInputStream) with a very restrictive whitelist of permitted classes.
    • Monitoring and Alerting: Implement robust logging and monitoring to detect attempts to deserialize unexpected classes or data.

Attack Surface: Reflection Abuse

  • Description: Reflection allows code to inspect and manipulate other code at runtime. If an attacker can control the inputs to reflection APIs, they might be able to bypass security checks, access private data, or execute arbitrary code.
  • Commons Lang Contribution: Utilities like ConstructorUtils, FieldUtils, MethodUtils, and TypeUtils heavily rely on reflection and provide the direct means for an attacker to exploit reflection vulnerabilities if inputs are not properly controlled.
  • Example: An application uses MethodUtils.invokeMethod() to call a method based on a user-provided method name. The attacker provides a malicious method name (e.g., java.lang.Runtime.exec) to execute arbitrary commands.
  • Impact: Bypass security restrictions, access to private data, potential for code execution (depending on the context).
  • Risk Severity: High
  • Mitigation Strategies:
    • Strict Input Validation: Thoroughly validate and sanitize any user-provided input that is used to construct class names, method names, or field names before passing them to reflection utilities. Use whitelisting.
    • Principle of Least Privilege: Run the application with the minimum necessary privileges.
    • Security Manager (Complex): Consider using a Java Security Manager, but be aware of the complexity.
    • Avoid Dynamic Reflection based on User Input: Refactor to avoid using reflection based on user input.