CVE-2025-30065 - Exploiting Arbitrary Code Execution in Apache Parquet’s Avro Module (Versions 1.15. and Earlier)

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Introduction

Apache Parquet is a widely used open source columnar storage format, notably in data engineering, data science, and big data projects. Many developers and enterprises rely on its robust performance and scalability, especially when paired with Apache Avro for storing complex data structures.

However, a critical security flaw, CVE-2025-30065, was uncovered in the Parquet-Avro module, affecting versions 1.15. and earlier. This vulnerability lets attackers execute arbitrary code on affected systems through crafted schema files – a serious risk for data lakes, ETL pipelines, and analytics platforms. In this article, I’ll break down what went wrong, show how exploitation works with example code, and guide you on staying safe.

What Is CVE-2025-30065?

*In short:*
CVE-2025-30065 arises from unsafe schema parsing in the parquet-avro module. Specifically, code deserializes Avro schemas without proper validation, opening the door to injection attacks.

Technical Root Cause

When Parquet reads Avro-formatted data, it trusts and parses schema files using Avro’s deserialization mechanisms. If a schema is attacker-controlled, it can embed Java classes or data that, when deserialized, execute code on your machine.

> This means anyone who can plant or send you a malicious .avsc (Avro schema) file, or maliciously crafted Parquet files containing schemas, might run code on your infrastructure — no user interaction needed.

How an Attack Works

1. Craft Evil Schema: The attacker creates a malicious Avro schema file with payloads that trigger deserialization logic.
2. Deliver to System: The schema is uploaded to systems where it will be parsed — cloud buckets, shared folders, data pipelines, etc.
3. Trigger Deserialization: When Parquet’s Avro module parses the file, it deserializes dangerous constructs, causing code execution (e.g., running a shell command, opening a reverse shell, etc.).

*Example of vulnerable code (Java):*

import org.apache.parquet.avro.AvroSchemaConverter;
import org.apache.avro.Schema;

public class ParquetSchemaTest {
    public static void main(String[] args) throws Exception {
        String evilSchema = new String(java.nio.file.Files.readAllBytes(
            java.nio.file.Paths.get("malicious.avsc")));
        Schema schema = new Schema.Parser().parse(evilSchema);
        // Vulnerable line: this triggers deserialization on the schema
        AvroSchemaConverter converter = new AvroSchemaConverter();
        converter.convert(schema);
    }
}

If malicious.avsc is crafted for exploitation, the above code can lead to arbitrary code execution when run.

*Malicious schema might abuse Avro’s logical types or attach Java object references, depending on the exact nature of the deserialization flaw.*

Real-World Impact

- Apache Spark / Hadoop: Any platform loading “user-supplied” schemas via Parquet + Avro may be at risk.

Data Lake Utilities: Scripts and data tools processing untrusted files are exposed.

- CI/CD Pipelines: Automated jobs using outdated Parquet libraries could be silently compromised.

Proof of Concept (PoC): How Attackers Could Exploit

*Here is a simplified PoC using a classic Java deserialization gadget chain (using ysoserial):*

Generate Payload

First, use ysoserial to create a payload that launches calc.exe (on Windows) or another harmless command:

Embed Payload in Schema

Insert the serialized payload into a schema definition, exploiting an unsafe data type or metadata field. Details are kept out to avoid abuse, but this demonstrates the general approach.

Load in Vulnerable Program

When the vulnerable Parquet-Avro parsing code (as above) reads the crafted schema file, the payload executes.

How to Fix and Protect Your Systems

Official Apache Parquet fix:
The Apache team patched this issue in version 1.15.1 (April 2025). Schema parsing is now hardened to reject potentially dangerous constructs.

Recommendation:
- Upgrade immediately to Parquet 1.15.1 or newer (Download Here).

Use input validation and sandboxing when dealing with external data.

Check if you’re affected:

References

- Apache Parquet CVE-2025-30065 Announcement
- Parquet 1.15.1 Release Notes
- Apache Avro Logical Types Spec
- ysoserial Java Deserialization Exploits
- CVE-2025-30065 at NVD

Takeaways

CVE-2025-30065 is a critical reminder to treat *all data schemas—especially from external or user sources—with suspicion*. If you manage or build data infrastructure with Apache Parquet and Avro, review and patch immediately – it only takes one bad schema file to compromise your host.

Timeline

Published on: 04/01/2025 08:15:15 UTC
Last modified on: 05/07/2025 13:15:49 UTC