CVE-2024-38820: Spring Framework Information Disclosure

CVE-2024-38820 Overview

The fix for CVE-2022-22968 made disallowedFields patterns in DataBinder case insensitive. However, String.toLowerCase() has some Locale dependent exceptions that could potentially result in fields not protected as expected.

Critical Impact
Improper case handling in DataBinder could lead to unauthorized field access.

Affected Products

vmware spring_framework
vmware spring_framework
vmware spring_framework

Discovery Timeline

Not Available - Vulnerability discovered by Not Available
Not Available - Responsible disclosure to VMware
Not Available - CVE CVE-2024-38820 assigned
Not Available - VMware releases security patch
2024-10-18 - CVE CVE-2024-38820 published to NVD
2024-11-29 - Last updated in NVD database

Technical Details for CVE-2024-38820

Vulnerability Analysis

The vulnerability arises from the improper handling of character case conversion in the DataBinder component of Spring Framework. The method String.toLowerCase() does not handle locale-specific exceptions effectively, potentially allowing access to fields that should be restricted.

Root Cause

The root cause is the use of String.toLowerCase() for case insensitivity, which does not cover all locale variations accurately.

Attack Vector

This vulnerability is exploitable over the network, allowing remote attackers to manipulate the DataBinder configurations if protective measures are not adequately applied.

java

// Example exploitation code (sanitized)
public class UnsafeBinder {
    public void bindData(DataBinder binder) {
        binder.setDisallowedFields("SENSITIVE_FIELD");
        // Potential bypass due to improper locale conversion
    }
}

Detection Methods for CVE-2024-38820

Indicators of Compromise

Unusual access to normally restricted fields
Unexpected changes in data binding behavior
Log entries with unauthorized field access

Detection Strategies

Utilize logging and monitoring tools to capture unauthorized access to restricted fields in DataBinder. Implement anomaly detection scripts to identify deviations in data access patterns.

Monitoring Recommendations

Set up centralized monitoring for all applications utilizing Spring Framework. Ensure all access logs are reviewed regularly for unauthorized access attempts.

How to Mitigate CVE-2024-38820

Immediate Actions Required

Audit existing DataBinder configurations
Implement case-insensitive checks manually where necessary
Ensure logging is enabled for all critical data access

Patch Information

Refer to the VMware advisory for the latest patch information and ensure all systems are updated to the patched version.

Workarounds

Review and manually enforce strict case-insensitive handling in all configurations using locale-aware transformations where needed.

bash

# Configuration example
echo 'DISALLOWED_FIELD=lowercaseonly' >> config.properties