CVE-2024-38808: VMware Spring Framework DoS Vulnerability

CVE-2024-38808 Overview

CVE-2024-38808 is a Denial of Service (DoS) vulnerability affecting VMware Spring Framework versions 5.3.0 through 5.3.38 and older unsupported versions. The vulnerability exists in the Spring Expression Language (SpEL) evaluation functionality, where a malicious actor can craft a specially designed SpEL expression that causes the application to become unresponsive or consume excessive resources.

Applications are vulnerable when they evaluate user-supplied SpEL expressions, making this particularly concerning for web applications and APIs that process dynamic expressions from untrusted sources.

Critical Impact

Attackers can cause denial of service conditions in Spring Framework applications that evaluate user-supplied SpEL expressions, potentially disrupting critical business operations and service availability.

Affected Products

• VMware Spring Framework versions 5.3.0 - 5.3.38
• NetApp Active IQ Unified Manager (Linux, VMware vSphere, Windows)
• NetApp OnCommand Insight

Discovery Timeline

• 2024-08-20 - CVE-2024-38808 published to NVD
• 2025-06-18 - Last updated in NVD database

Technical Details for CVE-2024-38808

Vulnerability Analysis

This vulnerability is classified as CWE-770 (Allocation of Resources Without Limits or Throttling). The core issue lies in how Spring Framework processes Spring Expression Language (SpEL) expressions without adequate resource constraints. When an application evaluates SpEL expressions provided by users, an attacker can submit expressions specifically designed to trigger resource exhaustion.

The vulnerability requires user interaction in the form of submitting the malicious expression through an application interface. Once processed, the crafted expression can cause the application to consume excessive CPU, memory, or other system resources, leading to degraded performance or complete service unavailability.

Root Cause

The root cause stems from insufficient resource limits during SpEL expression evaluation. The Spring Framework's SpEL parser and evaluator do not adequately restrict the complexity or execution time of expressions, allowing attackers to craft expressions that trigger computationally expensive operations or recursive evaluations that exhaust system resources.

Attack Vector

The attack is network-based and targets applications that accept and evaluate user-supplied SpEL expressions. An attacker would need to identify an endpoint or functionality that processes SpEL expressions and submit a specially crafted expression designed to cause resource exhaustion. The attack does not require authentication but does require user interaction to trigger the vulnerable code path.

Typical attack scenarios include:

• Web applications with dynamic templating features using SpEL
• REST APIs that accept SpEL expressions for filtering or querying
• Configuration interfaces that allow expression-based customization
• Any custom functionality that evaluates untrusted SpEL input

Detection Methods for CVE-2024-38808

Indicators of Compromise

• Unusual CPU or memory spikes on application servers running Spring Framework
• Increased response times or timeouts on endpoints that process SpEL expressions
• Application logs showing SpEL evaluation errors or stack overflow exceptions
• Repeated requests containing complex or deeply nested expression patterns

Detection Strategies

• Monitor application performance metrics for sudden resource utilization increases
• Implement request logging to capture incoming SpEL expressions for analysis
• Configure alerting on application response time degradation
• Review web application firewall logs for suspicious expression patterns

Monitoring Recommendations

• Enable detailed logging for SpEL evaluation operations
• Set up real-time monitoring for application resource consumption
• Implement circuit breakers to detect and isolate failing components
• Configure health checks to identify DoS conditions early

How to Mitigate CVE-2024-38808

Immediate Actions Required

• Audit applications to identify any endpoints that evaluate user-supplied SpEL expressions
• Upgrade Spring Framework to version 5.3.39 or later to receive the security fix
• Consider disabling user-supplied SpEL evaluation if not strictly required
• Implement input validation to restrict the complexity of accepted expressions

Patch Information

VMware has released security patches addressing this vulnerability. Organizations should upgrade to Spring Framework version 5.3.39 or later. For detailed patch information and upgrade guidance, refer to the Spring Security Advisory for CVE-2024-38808.

NetApp customers using affected products should consult the NetApp Security Advisory NTAP-20240920-0002 for product-specific guidance.

Workarounds

• Implement a whitelist of allowed SpEL expression patterns if user input is required
• Add timeout mechanisms around SpEL evaluation to prevent long-running expressions
• Use SimpleEvaluationContext instead of StandardEvaluationContext to limit expression capabilities
• Deploy rate limiting on endpoints that process SpEL expressions to mitigate abuse attempts

# Configuration example - Spring application properties
# Implement timeouts and resource limits for SpEL evaluation
spring.expression.timeout=5000
spring.expression.max-length=1000

# Enable enhanced security logging
logging.level.org.springframework.expression=DEBUG