CVE-2024-23080: Joda Time NullPointerException Vulnerability

CVE-2024-23080 Overview

CVE-2024-23080 is a reported Null Pointer Dereference vulnerability in Joda Time v2.12.5, specifically affecting the org.joda.time.format.PeriodFormat::wordBased(Locale) component. When triggered, this vulnerability can cause a NullPointerException that may lead to application crashes or denial of service conditions.

Important Note: This CVE is disputed by multiple third parties who believe there was not reasonable evidence to determine the existence of a vulnerability. The original submission may have been based on a tool that is not sufficiently robust for vulnerability identification.

Critical Impact

This disputed vulnerability could potentially allow attackers to trigger application crashes through malformed locale input, resulting in denial of service. However, the validity of this vulnerability remains contested.

Affected Products

• Joda Time v2.12.5
• Applications using org.joda.time.format.PeriodFormat::wordBased(Locale) method

Discovery Timeline

• 2024-04-10 - CVE-2024-23080 published to NVD
• 2024-11-21 - Last updated in NVD database

Technical Details for CVE-2024-23080

Vulnerability Analysis

The reported vulnerability is classified as CWE-476 (NULL Pointer Dereference). The issue is alleged to exist in the PeriodFormat.wordBased(Locale) method within the Joda Time library. When this method receives certain input conditions, it may not properly validate the locale parameter, potentially leading to a NullPointerException being thrown.

The network-based attack vector suggests that this vulnerability could be exploited remotely if an application exposes functionality that passes user-controlled locale data to the affected method. An attacker could potentially craft requests with specially formed locale parameters to trigger the null pointer dereference.

However, it's critical to note that this vulnerability is disputed. Third-party security researchers have questioned whether the reported behavior constitutes a legitimate security vulnerability, suggesting the original analysis may have been performed using automated tools that produced false positives.

Root Cause

The alleged root cause involves insufficient null-checking or input validation within the PeriodFormat.wordBased(Locale) method. When the method processes locale information for generating word-based period formats, it may encounter null values in certain code paths that are not properly handled, resulting in a NullPointerException.

Attack Vector

The vulnerability is reported to be exploitable via network access without authentication requirements. An attacker would need to identify an application that:

1. Uses Joda Time v2.12.5
2. Exposes the PeriodFormat.wordBased(Locale) functionality to user-controlled input
3. Passes untrusted locale data to the vulnerable method

The exploitation would involve sending crafted requests with specific locale parameters designed to trigger the null pointer condition within the library's internal processing logic.

Detection Methods for CVE-2024-23080

Indicators of Compromise

• Application crashes or service interruptions accompanied by NullPointerException stack traces referencing org.joda.time.format.PeriodFormat
• Unusual patterns of requests containing malformed or unexpected locale parameters
• Increased error rates in applications utilizing Joda Time date/time formatting functionality

Detection Strategies

• Monitor application logs for NullPointerException errors originating from Joda Time library components
• Implement application-level monitoring to detect repeated crashes or restarts in services using Joda Time
• Configure alerting for patterns consistent with denial of service attempts targeting date/time formatting endpoints

Monitoring Recommendations

• Enable verbose logging for applications using Joda Time to capture exception details
• Implement rate limiting on endpoints that process user-provided locale information
• Monitor for anomalous traffic patterns that may indicate exploitation attempts

How to Mitigate CVE-2024-23080

Immediate Actions Required

• Review application code to identify usage of PeriodFormat.wordBased(Locale) with user-controlled input
• Implement input validation to sanitize and validate locale parameters before passing to Joda Time methods
• Consider migrating to java.time (JSR-310) which is the modern replacement for Joda Time in Java 8+

Patch Information

As of the last update, no official patch has been released specifically for this vulnerability. Given the disputed nature of this CVE, the Joda Time maintainers may not consider this a valid security issue requiring a fix. Organizations should:

1. Monitor the GitHub Joda-Time Repository for any official statements or updates
2. Review the GitHub Gist Example referenced in the original report
3. Consider the disputed status when prioritizing remediation efforts

Workarounds

• Implement defensive null checks and input validation before calling PeriodFormat.wordBased(Locale)
• Wrap calls to the affected method in try-catch blocks to gracefully handle potential NullPointerExceptions
• Migrate to java.time API available in Java 8 and later, which provides equivalent functionality with improved null-safety
• Restrict access to endpoints that utilize locale-dependent period formatting functionality