attack-surface.md

Attack Surface Analysis for spring-projects/spring-framework

Attack Surface: 1. Deserialization Vulnerabilities

• Description: Exploitation of flaws in Java deserialization processes to execute arbitrary code or perform malicious actions by crafting malicious serialized objects.
• Spring Framework Contribution: Spring Framework, especially in older versions, might use Java serialization for session management, messaging (JMS), or remoting (RMI). If user-controlled data is deserialized by Spring components, it can become an attack vector.
• Example: An attacker crafts a malicious serialized Java object containing code to execute. This object is sent to the application, for example, as a session cookie managed by Spring Session. When Spring deserializes the session, the malicious code is executed, leading to Remote Code Execution (RCE).
• Impact: Remote Code Execution (RCE), data breach, system compromise.
• Risk Severity: Critical
• Mitigation Strategies:
  • Update Spring Framework: Use the latest Spring Framework versions with patched deserialization vulnerabilities.
  • Disable Java Serialization: Where possible, disable Java serialization in Spring configurations and prefer safer alternatives like JSON.
  • Object Filtering: Implement object filtering in Spring's deserialization mechanisms to restrict classes allowed for deserialization.
  • Input Validation: Validate and sanitize any data before deserialization within Spring components.

Attack Surface: 2. Expression Language Injection (SpEL Injection)

• Description: Injection of malicious code into Spring Expression Language (SpEL) expressions, allowing attackers to execute arbitrary code or access sensitive data.
• Spring Framework Contribution: Spring Framework uses SpEL extensively for dynamic configuration, data binding in Spring MVC, and security expressions in Spring Security. If user input is directly used in SpEL expressions within Spring components without sanitization, it creates an injection point.
• Example: A Spring MVC controller uses SpEL to dynamically evaluate a property based on user input in a request parameter. An attacker injects a malicious SpEL expression like #{T(java.lang.Runtime).getRuntime().exec('malicious command')} through the parameter, leading to command execution on the server by Spring's SpEL evaluation engine.
• Impact: Remote Code Execution (RCE), data exfiltration, privilege escalation.
• Risk Severity: Critical
• Mitigation Strategies:
  • Avoid User Input in SpEL: Do not directly use user input in SpEL expressions within Spring components.
  • Parameterized Expressions: Use parameterized SpEL expressions to separate code from data when using SpEL in Spring.
  • Input Sanitization: Sanitize user input if it absolutely must be used in SpEL expressions within Spring.
  • Restricted SpEL Context: Use a restricted SpEL context with limited access to sensitive objects and methods when using SpEL in Spring.

Attack Surface: 3. Mass Assignment Vulnerabilities

• Description: Exploiting Spring MVC's automatic data binding feature to modify unintended object properties by manipulating request parameters.
• Spring Framework Contribution: Spring MVC's parameter binding automatically maps HTTP request parameters to object properties. If Spring MVC's binding mechanism is not properly controlled, attackers can modify fields that should not be user-modifiable through crafted requests.
• Example: A Spring MVC controller binds request parameters directly to a User entity. An attacker adds an extra parameter like isAdmin=true in the HTTP request. If the isAdmin field in the User entity is accessible and not properly protected in the Spring MVC binding configuration, the attacker can elevate their privileges to administrator.
• Impact: Privilege escalation, data manipulation, unauthorized access.
• Risk Severity: High
• Mitigation Strategies:
  • Data Transfer Objects (DTOs): Use DTOs for request binding in Spring MVC controllers instead of directly binding to domain entities.
  • Field Whitelisting (Allowed Fields): Explicitly configure allowed fields for binding in Spring MVC and reject any unexpected parameters.
  • Validation: Implement validation rules using Spring Validation framework to ensure only valid data is bound to objects by Spring MVC.

Attack Surface: 4. Path Traversal Vulnerabilities (File Serving via Spring MVC)

• Description: Accessing files outside the intended web root directory by manipulating file paths in requests when Spring MVC is configured to serve static files.
• Spring Framework Contribution: Spring MVC can be configured to serve static files using <mvc:resources/> or programmatically. Misconfigurations or vulnerabilities in Spring MVC's path handling logic can allow attackers to bypass intended directory restrictions and access arbitrary files on the server.
• Example: A Spring MVC application is configured to serve static files from a /static directory. An attacker crafts a request like /static/../../../../etc/passwd to attempt to access the system's password file, exploiting potential path traversal flaws in Spring MVC's resource handling.
• Impact: Information disclosure, access to sensitive files, potential system compromise.
• Risk Severity: High
• Mitigation Strategies:
  • Secure Static Resource Handling Configuration: Carefully configure static resource handling in Spring MVC, ensuring proper path sanitization and restriction.
  • Avoid Serving Sensitive Files via Spring MVC: Do not serve sensitive files directly through Spring MVC's static resource handling.
  • Input Validation in Custom Handlers: If using custom Spring MVC handlers for file serving, implement robust input validation and sanitization for file paths.
  • Dedicated Web Server for Static Content: Consider using a hardened web server (like Nginx or Apache) in front of the Spring application to handle static content serving, as they are often more robust against path traversal attacks.

Attack Surface: 5. Cross-Site Scripting (XSS) Vulnerabilities (View Rendering in Spring MVC)

• Description: Injecting malicious scripts into web pages rendered by Spring MVC views (JSP, Thymeleaf, etc.) that are executed in users' browsers, often by exploiting insufficient output encoding.
• Spring Framework Contribution: Spring MVC uses view technologies to render dynamic content. If Spring MVC views (JSP, Thymeleaf, FreeMarker, etc.) do not properly escape user-provided data before rendering it in HTML, XSS vulnerabilities can occur.
• Example: A Spring MVC application displays user comments on a webpage rendered using Thymeleaf. If user comments are displayed using unescaped output (e.g., th:utext instead of th:text and the developer forgets to manually escape), an attacker can inject a malicious script in a comment like <script>alert('XSS')</script>. When other users view the comment rendered by Spring MVC, the script executes in their browsers.
• Impact: Account compromise, session hijacking, website defacement, malware distribution.
• Risk Severity: High
• Mitigation Strategies:
  • Use Templating Engine Escaping: Consistently use templating engine's built-in escaping mechanisms provided by Spring MVC's view technologies (e.g., Thymeleaf's th:text, JSP's JSTL <c:out>).
  • Context-Sensitive Encoding in Views: Implement context-sensitive output encoding in Spring MVC views based on where data is rendered (HTML, JavaScript, CSS, URL).
  • Content Security Policy (CSP): Utilize CSP headers in Spring MVC applications to mitigate the impact of XSS attacks.

Attack Surface: 6. Authentication and Authorization Bypass (Spring Security Misconfiguration)

• Description: Circumventing authentication or authorization mechanisms due to misconfigurations in Spring Security, a core module within the Spring Framework ecosystem, allowing unauthorized access to protected resources.
• Spring Framework Contribution: Spring Security is the standard security framework for Spring applications. Misconfigurations in Spring Security's configuration, filters, or access rules directly lead to authentication and authorization bypass vulnerabilities.
• Example: A Spring Security configuration incorrectly uses permitAll() for an endpoint that should be protected, allowing anonymous access to sensitive data. Or, a custom WebSecurityConfigurerAdapter in Spring Security has a flawed access control rule, granting access to users who should not have it, bypassing intended authorization checks enforced by Spring Security.
• Impact: Unauthorized access to sensitive data, privilege escalation, data breach, system compromise.
• Risk Severity: Critical
• Mitigation Strategies:
  • Thorough Spring Security Configuration Review: Carefully review and test all Spring Security configurations, including WebSecurityConfigurerAdapter implementations and security rules.
  • Follow Spring Security Best Practices: Adhere to security best practices and guidelines specifically for Spring Security configuration and usage.
  • Role-Based Access Control (RBAC) or ABAC Implementation: Implement RBAC or Attribute-Based Access Control (ABAC) correctly using Spring Security's features.
  • Input Validation in Security Logic: Implement input validation within custom authentication providers or authorization logic in Spring Security.
  • Regular Security Audits of Spring Security Configuration: Regularly audit Spring Security configurations and access control rules to identify and rectify misconfigurations.

Attack Surface: 7. SQL Injection Vulnerabilities (Spring Data JPA/JDBC)

• Description: Injecting malicious SQL code into database queries executed by Spring Data JPA or JDBC, allowing attackers to manipulate the database, bypass security measures, or access sensitive data.
• Spring Framework Contribution: Spring Data JPA and JDBC simplify database access in Spring applications. However, using native queries, dynamic JPQL/HQL, or custom repository methods with unsanitized user input within Spring Data repositories can introduce SQL injection vulnerabilities.
• Example: A Spring Data JPA repository uses a @Query annotation with a native SQL query that concatenates user-provided input without proper parameterization. An attacker can inject SQL code through this input, leading to unauthorized data access or modification via the Spring Data repository.
• Impact: Data breach, data manipulation, data deletion, authentication bypass, potential Remote Code Execution (in some database configurations).
• Risk Severity: Critical
• Mitigation Strategies:
  • Always Use Parameterized Queries in Spring Data: Always use parameterized queries or prepared statements when working with databases through Spring Data JPA or JDBC, especially for native queries or custom queries.
  • Avoid Dynamic SQL Construction in Spring Data: Avoid constructing SQL queries dynamically using string concatenation with user input within Spring Data repositories.
  • Utilize Spring Data Query Methods and Specifications: Prefer using Spring Data JPA's query methods and specifications, as they often provide built-in protection against SQL injection when used correctly.
  • Code Review and Audits of Spring Data Repositories: Carefully review and audit native queries and custom repository methods in Spring Data for potential SQL injection vulnerabilities.

Attack Surface: 8. Exposure of Sensitive Actuator Endpoints (Spring Boot Actuator)

• Description: Unprotected access to Spring Boot Actuator endpoints, a feature of Spring Boot (part of the Spring ecosystem), revealing sensitive information about the application and its environment.
• Spring Framework Contribution: Spring Boot Actuator, built upon the Spring Framework, provides management and monitoring endpoints. If these endpoints are exposed without proper authentication and authorization configured through Spring Security (or other means), attackers can access sensitive data exposed by Actuator.
• Example: Spring Boot Actuator endpoints like /env, /configprops, /metrics, or /health are enabled but not secured with Spring Security. An attacker can access these endpoints to view environment variables, configuration details managed by Spring Boot, application metrics, and potentially sensitive information about the application's internals and infrastructure managed by Spring Boot and Spring Framework.
• Impact: Information disclosure, reconnaissance for further attacks, potential system compromise (if shutdown endpoint is exposed and exploitable).
• Risk Severity: High (depending on exposed endpoints and sensitivity of information)
• Mitigation Strategies:
  • Secure Actuator Endpoints with Spring Security: Secure Spring Boot Actuator endpoints using Spring Security's authentication and authorization mechanisms.
  • Restrict Actuator Access based on Roles/IPs: Restrict access to actuator endpoints to authorized users or roles using Spring Security, or limit access based on IP addresses.
  • Disable Sensitive Actuator Endpoints in Production: Consider disabling or limiting the exposure of sensitive actuator endpoints in production environments if they are not strictly necessary.
  • Network Segmentation for Actuator: Isolate actuator endpoints to internal networks if possible, preventing direct external access.