A critical vulnerability has been discovered in Apache Parquet, a popular open-source columnar data file format, allowing attackers to execute arbitrary code on vulnerable instances. The flaw, tracked as CVE-2025-30065, is a deserialization issue in Parquet's Java library that enables the execution of maliciously crafted Parquet files.

The vulnerability affects Java implementations of Apache Parquet, specifically versions prior to 1.15.1. According to Endor Labs, the issue was introduced in version 1.8.0, and all historic versions should be reviewed. The Parquet-avro module within the library allows deserialization of untrusted data, enabling the execution of remote code sent in the form of crafted Parquet files.

The implications of this vulnerability are severe. Any application or service that uses the Java library, including popular big-data frameworks like Hadoop, Spark, and Flink, are susceptible to attacks. The resulting remote code execution (RCE) on victim systems can allow attackers to take control of the systems, tamper with or steal data, install malware, or disrupt services.

Fortunately, there have been no reported exploit attempts using CVE-2025-30065 as of publication. Apache silently pushed a fix with the release of 1.15.1 on March 16, 2025, with a GitHub redirect to changes made in the update. However, Endor Labs advises prompt patching of the vulnerability, cautioning that the absence of reported attacks should not delay action as the issue is now public knowledge.

One mitigating factor for vulnerable organizations is the requirement for user interaction for a successful exploitation. Only a malicious Parquet file imported by the user into their systems can trigger the vulnerability. However, this may not provide long-term protection, as demonstrated by the recent critical flaw found in Apache Tomcat, which was exploited within 30 hours of public disclosure.

The vulnerability poses significant threats to the confidentiality, integrity, and availability of affected systems. Organizations using Parquet for their big-data and analytics stacks must prioritize patching to prevent potential system takeover. As the vulnerability is now public knowledge, it is essential to take immediate action to prevent potential attacks.

In conclusion, the discovery of this critical flaw in Apache Parquet serves as a reminder of the importance of timely patching and vulnerability management. As big data systems continue to play a vital role in modern organizations, it is crucial to prioritize their security and integrity to prevent devastating consequences.