CVE-2025-3588: jsonschema2pojo Buffer Overflow Vulnerability

CVE-2025-3588 Overview

A stack-based buffer overflow vulnerability has been discovered in joelittlejohn jsonschema2pojo version 1.2.2. This issue affects the apply function within the file org/jsonschema2pojo/rules/SchemaRule.java of the JSON File Handler component. The vulnerability allows local attackers to manipulate input in a way that leads to a stack-based buffer overflow condition.

Critical Impact

Local attackers with low privileges can exploit this vulnerability to potentially cause memory corruption, affecting the confidentiality, integrity, and availability of the affected system. The exploit has been publicly disclosed, and the vendor has not responded to early disclosure attempts.

Affected Products

• joelittlejohn jsonschema2pojo 1.2.2
• JSON File Handler component (org/jsonschema2pojo/rules/SchemaRule.java)

Discovery Timeline

• April 14, 2025 - CVE-2025-3588 published to NVD
• April 15, 2025 - Last updated in NVD database

Technical Details for CVE-2025-3588

Vulnerability Analysis

This vulnerability is classified as CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer). The flaw exists in the apply function of the SchemaRule.java file, which is responsible for processing JSON schema files within the jsonschema2pojo library. When handling specially crafted JSON input, the function fails to properly validate the boundaries of operations, leading to a stack-based buffer overflow condition.

The jsonschema2pojo library is commonly used by Java developers to generate Plain Old Java Objects (POJOs) from JSON schema definitions. This makes the vulnerability particularly concerning for development environments and build pipelines that process untrusted JSON schema files.

Root Cause

The root cause of this vulnerability lies in improper memory bounds checking within the apply function of SchemaRule.java. When processing JSON file input, the function does not adequately validate the size of input data before performing memory operations, allowing attackers to overflow the stack buffer.

Memory corruption vulnerabilities of this type (CWE-119) occur when software performs operations on a memory buffer but can read from or write to a memory location outside the intended boundary of that buffer. In this case, the stack-based nature of the overflow means the attack surface is on the call stack, potentially allowing manipulation of return addresses or local variables.

Attack Vector

The attack requires local access to the system where jsonschema2pojo is running. An attacker with low-level privileges can craft a malicious JSON file that, when processed by the vulnerable apply function, triggers the buffer overflow condition. The exploit has been publicly disclosed, increasing the risk of exploitation attempts.

For detailed technical analysis of the vulnerability mechanism, refer to the GitHub Issue Discussion and the VulDB entry.

Detection Methods for CVE-2025-3588

Indicators of Compromise

• Unexpected application crashes or segmentation faults when processing JSON schema files
• Abnormal memory consumption patterns in Java applications using jsonschema2pojo
• Stack trace errors referencing org/jsonschema2pojo/rules/SchemaRule.java in the apply function
• Suspicious JSON schema files with unusually large or deeply nested structures

Detection Strategies

• Monitor application logs for exceptions originating from the SchemaRule.java component
• Implement file integrity monitoring on JSON schema input directories
• Deploy runtime application self-protection (RASP) solutions to detect buffer overflow attempts
• Use static analysis tools to identify usage of jsonschema2pojo version 1.2.2 in codebases

Monitoring Recommendations

• Enable verbose logging for jsonschema2pojo operations to capture processing anomalies
• Set up alerts for abnormal Java process behavior including unexpected terminations
• Monitor build pipeline logs for failures related to JSON schema processing
• Implement memory usage thresholds and alerts for applications using this library

How to Mitigate CVE-2025-3588

Immediate Actions Required

• Audit your applications and build systems for usage of jsonschema2pojo version 1.2.2
• Restrict JSON schema input to trusted sources only until a patch is available
• Implement input validation for JSON schema files before processing
• Consider temporarily switching to alternative JSON schema processing libraries if feasible
• Monitor the official GitHub repository for vendor response and patches

Patch Information

At the time of this publication, the vendor has not responded to disclosure attempts and no official patch is available. Organizations should monitor the jsonschema2pojo GitHub repository for security updates and new releases. The vulnerability was reported through proper disclosure channels, but the vendor has not acknowledged or addressed the issue.

Workarounds

• Implement strict input validation to sanitize JSON schema files before processing with jsonschema2pojo
• Run jsonschema2pojo in a sandboxed or containerized environment with limited privileges
• Use application-level controls to restrict which users can submit JSON schema files for processing
• Consider implementing file size limits and schema complexity limits as defensive measures

# Configuration example: Run jsonschema2pojo with memory limits in containerized environment
# Docker example with resource constraints
docker run --memory="512m" --cpus="1.0" \
  --security-opt=no-new-privileges:true \
  --read-only \
  -v /path/to/trusted/schemas:/schemas:ro \
  your-jsonschema2pojo-app