CVE-2020-35451 in Oozie
Summary
by MITRE • 03/10/2021
There is a race condition in OozieSharelibCLI in Apache Oozie before version 5.2.1 which allows a malicious attacker to replace the files in Oozie's sharelib during it's creation.
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Analysis
by VulDB Data Team • 03/29/2021
The vulnerability identified as CVE-2020-35451 represents a critical race condition flaw within the OozieSharelibCLI component of Apache Oozie versions prior to 5.2.1. This race condition occurs during the creation and initialization of Oozie's sharelib directory structure, which serves as the foundational repository for all Oozie workflow libraries and extensions. The sharelib functionality is essential for Oozie's operation as it contains the necessary JAR files and configuration resources that enable workflow execution across distributed computing environments.
The technical implementation of this vulnerability stems from improper synchronization mechanisms during the sharelib creation process. When Oozie initializes its sharelib directory, the system does not adequately protect against concurrent file operations that could occur between the creation of directory structures and the subsequent population of files. This timing gap allows an attacker to manipulate the file system by replacing or modifying critical files during the brief window when the sharelib is being constructed. The race condition specifically manifests when multiple processes or threads attempt to access or modify the same file system resources simultaneously without proper locking mechanisms.
From an operational perspective, this vulnerability presents a severe security risk that could enable privilege escalation and arbitrary code execution within the Oozie environment. An attacker exploiting this race condition could substitute legitimate library files with malicious equivalents, potentially leading to unauthorized code execution on the Oozie server. The impact extends beyond simple file replacement as it could compromise the integrity of the entire workflow processing system, affecting data processing pipelines and potentially exposing sensitive enterprise information. This vulnerability directly aligns with CWE-367, which categorizes time-of-check to time-of-use (TOCTOU) flaws, and represents a classic example of a race condition that can be exploited in distributed computing environments.
The exploitation of this vulnerability requires an attacker to have access to the system where Oozie is running and the ability to perform file system operations during the sharelib creation window. This typically involves having sufficient privileges to write to the Oozie sharelib directory or the underlying file system. The attack vector is particularly concerning because it can be executed without requiring elevated privileges beyond what is already available to the Oozie service account. Security practitioners should note that this vulnerability could be leveraged as part of a broader attack chain, potentially serving as a foothold for more extensive system compromise within enterprise environments that rely heavily on Apache Oozie for workflow automation and data processing orchestration.
Organizations utilizing Apache Oozie should immediately implement mitigation strategies including upgrading to version 5.2.1 or later, which includes proper synchronization mechanisms to prevent the race condition. Additional protective measures include implementing file system access controls, monitoring for unauthorized file modifications during sharelib creation processes, and conducting regular security assessments of the Oozie environment. The vulnerability also highlights the importance of proper input validation and file system security in distributed computing platforms, as similar race conditions could potentially exist in other components of the Apache ecosystem or similar workflow management systems. This issue demonstrates the critical need for robust concurrency control mechanisms in enterprise software systems where multiple processes may interact with shared resources during initialization phases.