CVE-2021-41561 in Parquet
Summary
by MITRE • 12/20/2021
Improper Input Validation vulnerability in Parquet-MR of Apache Parquet allows an attacker to DoS by malicious Parquet files. This issue affects Apache Parquet-MR version 1.9.0 and later versions.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 07/28/2025
The vulnerability CVE-2021-41561 represents a critical improper input validation flaw within Apache Parquet-MR library version 1.9.0 and subsequent releases. This security weakness resides in the Parquet file format processing component that is widely used for efficient data storage and retrieval in big data environments. The vulnerability specifically manifests when the system processes maliciously crafted Parquet files that contain malformed or excessively complex data structures. Such files can trigger abnormal behavior in the Parquet-MR processing pipeline, leading to system resource exhaustion and ultimately causing denial of service conditions that severely impact data processing workflows.
The technical implementation of this vulnerability stems from insufficient validation mechanisms within the Parquet file parser that fails to properly sanitize incoming data structures. When an attacker crafts a Parquet file containing recursive or deeply nested data elements, the parsing logic becomes susceptible to stack overflow conditions or excessive memory consumption patterns. The flaw operates at the data parsing layer where the system attempts to deserialize complex nested schemas without adequate bounds checking or resource limiting measures. This improper handling of input validation creates a pathway for attackers to exploit the system through carefully constructed malicious payloads that can cause the processing engine to consume excessive computational resources.
The operational impact of CVE-2021-41561 extends beyond simple denial of service conditions as it can disrupt entire data processing pipelines and compromise system availability for legitimate users. Organizations utilizing Apache Parquet-MR in their big data architectures face significant risks when exposed to this vulnerability, particularly in environments where automated processing jobs or real-time data ingestion systems are in operation. The vulnerability can be exploited by attackers who gain access to systems capable of processing Parquet files, potentially including unauthorized users with upload privileges or through supply chain attacks targeting data processing components. The cascading effect of such attacks can lead to extended downtime for data services, increased operational costs, and potential data loss scenarios in critical business applications.
Mitigation strategies for this vulnerability should focus on immediate patching of affected Apache Parquet-MR installations to version 1.12.0 or later where the input validation issues have been addressed. Organizations must implement comprehensive monitoring and logging of Parquet file processing activities to detect anomalous behavior patterns that may indicate exploitation attempts. Network segmentation and access controls should be enforced to limit the ability of unauthorized parties to upload or process potentially malicious Parquet files within the system infrastructure. Additionally, implementing input validation layers and resource quotas for data processing jobs can provide additional defense-in-depth measures. The vulnerability aligns with CWE-20, which addresses improper input validation, and represents a significant concern for ATT&CK technique T1499, specifically focusing on network denial of service attacks through resource exhaustion. Regular security assessments and vulnerability scanning of big data processing environments should be conducted to identify and remediate similar input validation weaknesses that may exist in related components of the data processing stack.