CVE-2025-12383: Eclipse Jersey Race Condition Vulnerability

CVE-2025-12383 Overview

CVE-2025-12383 is a critical race condition vulnerability affecting Eclipse Jersey, a popular RESTful web services framework for Java. The vulnerability exists in specific versions of Eclipse Jersey where a race condition can cause critical SSL configurations to be ignored. This includes security-critical settings such as mutual authentication, custom key/trust stores, and other SSL/TLS security configurations. Under normal circumstances, this issue may manifest as an SSLHandshakeException, but under certain conditions, it could lead to unauthorized trust in insecure servers, potentially enabling man-in-the-middle attacks.

Critical Impact

A race condition in Eclipse Jersey can bypass SSL security configurations, potentially allowing applications to establish connections with untrusted servers and exposing sensitive communications to interception.

Affected Products

• Eclipse Jersey 2.45
• Eclipse Jersey 3.0.16
• Eclipse Jersey 3.1.9

Discovery Timeline

• 2025-11-18 - CVE-2025-12383 published to NVD
• 2026-01-16 - Last updated in NVD database

Technical Details for CVE-2025-12383

Vulnerability Analysis

This vulnerability is classified as CWE-362 (Race Condition). The flaw exists in how Eclipse Jersey handles SSL/TLS configuration during connection establishment. When multiple threads attempt to configure or use SSL connections concurrently, a race condition can occur that results in critical security settings being bypassed or ignored entirely.

The race condition is particularly dangerous because SSL/TLS configurations are fundamental to establishing secure communications. When these configurations are ignored, the application may:

• Accept connections from servers without proper certificate validation
• Bypass mutual authentication requirements
• Ignore custom trust store configurations
• Establish insecure connections without the application's knowledge

The vulnerability requires a network-accessible attack vector with high complexity, as the race condition must be triggered under specific timing circumstances. However, the potential impact on confidentiality and integrity is severe, as successful exploitation could compromise the entire security posture of SSL/TLS communications.

Root Cause

The root cause of this vulnerability is a race condition in Eclipse Jersey's SSL configuration handling. When multiple threads concurrently access or modify SSL connection parameters, there is a window where security configurations may not be properly applied. This is a Time-of-Check Time-of-Use (TOCTOU) style vulnerability where the SSL configuration state can change between when it is set and when it is actually used to establish a connection.

The lack of proper synchronization mechanisms around SSL configuration allows one thread's security settings to potentially be overwritten or ignored by another thread's operations, leading to connections being established with incomplete or incorrect security parameters.

Attack Vector

The attack vector for this vulnerability is network-based. An attacker positioned as a man-in-the-middle could potentially exploit this race condition to intercept communications that should have been protected by mutual TLS authentication or custom trust configurations.

The exploitation scenario involves triggering the race condition at a precise moment when an application is establishing SSL connections. If successful, the attacker could cause the application to:

1. Connect to a malicious server while bypassing certificate validation
2. Accept connections without requiring proper client certificates
3. Ignore custom trust anchors designed to limit acceptable certificate authorities

While this vulnerability requires specific timing conditions to exploit, the consequences of successful exploitation are severe, as it undermines the fundamental security guarantees of SSL/TLS.

Detection Methods for CVE-2025-12383

Indicators of Compromise

• Unexpected SSLHandshakeException errors in application logs that occur intermittently
• Successful SSL/TLS connections to servers that should fail certificate validation
• Inconsistent behavior in mutual TLS authentication where some connections bypass client certificate requirements
• Log entries showing SSL connections established without expected trust store validations

Detection Strategies

• Monitor application logs for sporadic SSLHandshakeException errors that may indicate race condition occurrences
• Implement network traffic analysis to detect connections to unexpected or untrusted endpoints
• Review Eclipse Jersey version deployments across your infrastructure to identify affected instances
• Audit SSL/TLS connection patterns for anomalies in certificate validation behavior

Monitoring Recommendations

• Enable detailed SSL/TLS logging in Eclipse Jersey applications to capture connection establishment details
• Implement alerting on unexpected certificate validation failures or bypasses
• Monitor thread contention metrics in applications using SSL connections heavily
• Deploy network security monitoring to detect potential man-in-the-middle attack indicators

How to Mitigate CVE-2025-12383

Immediate Actions Required

• Inventory all applications using Eclipse Jersey versions 2.45, 3.0.16, or 3.1.9
• Review the Eclipse CVE Assignment Issue for vendor guidance and patch availability
• Prioritize patching for applications that handle sensitive data over SSL/TLS connections
• Consider implementing additional network-level security controls while awaiting patches

Patch Information

Organizations should monitor the official Eclipse Jersey security advisories for patch releases addressing this vulnerability. The vendor has documented this issue in their security CVE assignment tracker. Upgrading to patched versions of Eclipse Jersey is the recommended remediation approach once patches are available.

Workarounds

• Reduce concurrent SSL connection establishment where possible to minimize race condition windows
• Implement additional certificate validation at the application layer as a defense-in-depth measure
• Consider using network-level TLS termination with strict certificate pinning
• Deploy Web Application Firewalls (WAF) or API gateways with their own SSL/TLS validation as an additional security layer
• Limit thread pool sizes for connection handling to reduce concurrent SSL configuration access

# Configuration example - Verify Eclipse Jersey versions in Maven projects
mvn dependency:tree | grep jersey

# Check for affected versions in Gradle projects
gradle dependencies | grep jersey