CVE-2025-41248: Spring Security Auth Bypass Vulnerability

CVE-2025-41248 Overview

CVE-2025-41248 is an authorization bypass vulnerability in Spring Security's annotation detection mechanism. The flaw occurs when Spring Security fails to correctly resolve security annotations on methods within type hierarchies that use parameterized super types with unbounded generics. This can lead to authorization bypass when using @PreAuthorize and other method security annotations in applications that have enabled the @EnableMethodSecurity feature.

Applications are vulnerable if they use Spring Security's @EnableMethodSecurity feature in combination with security annotations on methods in generic superclasses or generic interfaces. Applications that do not use @EnableMethodSecurity or do not apply security annotations to methods in generic type hierarchies are not affected.

Critical Impact

Attackers can bypass method-level authorization controls, potentially gaining unauthorized access to protected resources and functionality in affected Spring Security applications.

Affected Products

• Spring Security applications using @EnableMethodSecurity
• Applications with security annotations on methods in generic superclasses
• Applications with security annotations on methods in generic interfaces

Discovery Timeline

• 2025-09-16 - CVE CVE-2025-41248 published to NVD
• 2025-09-16 - Last updated in NVD database

Technical Details for CVE-2025-41248

Vulnerability Analysis

This vulnerability stems from a flaw in how Spring Security's annotation detection mechanism processes type hierarchies involving unbounded generics. When a method is annotated with security annotations like @PreAuthorize, @PostAuthorize, @Secured, or similar method security annotations, Spring Security must correctly resolve these annotations during runtime to enforce authorization policies.

The issue arises specifically in scenarios where a method is defined in a generic superclass or interface with unbounded type parameters (e.g., <T>). When a concrete class extends or implements such a parameterized type, the annotation detection mechanism may fail to properly traverse the type hierarchy and locate the security annotation. As a result, the security constraint is not applied, allowing unauthorized access to the protected method.

This vulnerability is classified under CWE-289 (Authentication Bypass by Alternate Name), as the annotation detection failure effectively allows bypassing the intended authentication and authorization mechanisms.

Root Cause

The root cause lies in Spring Security's annotation resolution logic when dealing with parameterized super types containing unbounded generics. The framework's reflection-based annotation discovery fails to account for certain edge cases in Java's type erasure and generic type hierarchies, leading to security annotations being overlooked during method invocation.

When a class hierarchy involves generic types like interface Service<T> with a method annotated with @PreAuthorize, and a concrete implementation like class UserService implements Service<User>, the annotation detection mechanism may not correctly map the concrete method to its annotated counterpart in the generic interface.

Attack Vector

This vulnerability is exploitable over the network without requiring any privileges or user interaction. An attacker can exploit this vulnerability by:

1. Identifying endpoints or service methods in the target application that rely on method-level security annotations
2. Determining if those methods are defined in generic superclasses or interfaces with unbounded type parameters
3. Directly invoking the vulnerable methods, bypassing the intended authorization checks
4. Gaining unauthorized access to protected functionality or sensitive data

Since the vulnerability allows bypassing authorization controls entirely, the impact is primarily on confidentiality, enabling unauthorized information disclosure.

The exploitation does not require sophisticated techniques—once an attacker identifies an affected endpoint, they can simply call it directly without the expected authorization restrictions being enforced.

Detection Methods for CVE-2025-41248

Indicators of Compromise

• Unexpected access to protected resources by unauthenticated or low-privileged users
• Application logs showing method invocations without corresponding authorization audit entries
• Access pattern anomalies where protected methods are called without proper authentication context
• Audit log gaps where expected authorization checks are missing

Detection Strategies

• Review application code for method security annotations (@PreAuthorize, @PostAuthorize, @Secured) applied to methods in generic interfaces or abstract classes
• Analyze application logs for unauthorized access attempts to protected endpoints
• Implement integration tests that verify authorization is enforced on methods inherited from generic type hierarchies
• Use static analysis tools to identify security annotations in generic type hierarchies

Monitoring Recommendations

• Enable detailed audit logging for all method security decisions in Spring Security
• Monitor for access patterns to protected resources that bypass expected authorization flows
• Set up alerts for successful access to sensitive methods without corresponding authorization events
• Implement runtime verification of annotation resolution in security-critical code paths

How to Mitigate CVE-2025-41248

Immediate Actions Required

• Review your application for use of @EnableMethodSecurity with security annotations on generic superclasses or interfaces
• Apply security annotations directly on concrete implementation methods as a temporary workaround
• Upgrade Spring Security to the patched version when available from the vendor
• Implement additional authorization checks at the controller or service layer as defense-in-depth

Patch Information

Refer to the Spring Security Advisory for CVE-2025-41248 for official patch information and updated versions. This CVE is published in conjunction with CVE-2025-41249, and organizations should review both advisories to ensure comprehensive remediation.

Workarounds

• Move security annotations from generic interfaces/superclasses to concrete implementation methods
• Implement programmatic authorization checks using SecurityContextHolder instead of relying solely on annotation-based security
• Add redundant authorization logic at the web layer (controller level) to prevent unauthorized access
• Consider using aspect-oriented programming (AOP) to enforce authorization independently of the annotation mechanism

# Configuration example - Verify @EnableMethodSecurity usage in your application
# Search for affected patterns in your codebase:
grep -r "@EnableMethodSecurity" src/
grep -r "@PreAuthorize" src/ | grep -E "(interface|abstract class)"
grep -r "@Secured" src/ | grep -E "(interface|abstract class)"

# Review generic type hierarchies with security annotations
find src/ -name "*.java" -exec grep -l "<T>" {} \; | xargs grep -l "@PreAuthorize"