CVE-2017-3166 in Hadoop
Summary
by MITRE
In Apache Hadoop versions 2.6.1 to 2.6.5, 2.7.0 to 2.7.3, and 3.0.0-alpha1, if a file in an encryption zone with access permissions that make it world readable is localized via YARN's localization mechanism, that file will be stored in a world-readable location and can be shared freely with any application that requests to localize that file.
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Analysis
by VulDB Data Team • 01/10/2023
The vulnerability described in CVE-2017-3166 represents a critical security flaw in Apache Hadoop's encryption zone access control mechanisms. This issue affects multiple versions of the Hadoop ecosystem including 2.6.1 through 2.6.5, 2.7.0 through 2.7.3, and the initial 3.0.0-alpha1 release. The flaw specifically targets the interaction between Hadoop's encryption zone functionality and YARN's application localization process, creating a path for unauthorized data exposure that violates fundamental security principles of data protection and access control.
The technical implementation of this vulnerability stems from how Hadoop handles file localization within encryption zones. When a file is stored within an encryption zone and has world-readable permissions, the system fails to properly enforce access controls during the YARN localization process. This process allows applications to request and receive localized copies of files, but the vulnerability enables these localized copies to be created in locations that maintain the world-readable permissions of the original file. The flaw essentially bypasses the intended access control mechanisms that should prevent unauthorized sharing of encrypted data, creating a scenario where sensitive information can be freely accessed by any application that requests the file.
The operational impact of CVE-2017-3166 is significant and far-reaching within Hadoop environments. Organizations using affected versions of Hadoop face potential data breaches where files within encryption zones can be accessed by unauthorized applications or users. This vulnerability directly contradicts the security model of encryption zones, which are designed to protect sensitive data through both encryption and access control mechanisms. The risk is compounded by the fact that the vulnerability affects the core YARN localization functionality, which is fundamental to how applications operate within Hadoop clusters, potentially exposing large volumes of sensitive data across multiple applications and users.
This vulnerability maps directly to CWE-276, which addresses improper file permissions and access control issues in software systems. The flaw represents a classic case of inadequate privilege separation where the system fails to properly manage file access controls during file operations. From an ATT&CK framework perspective, this vulnerability enables techniques related to privilege escalation and data exposure, as it allows unauthorized access to encrypted data that should remain protected. The vulnerability also aligns with ATT&CK tactic TA0006 (Credential Access) and technique T1078 (Valid Accounts) since it enables unauthorized access to data through legitimate application access patterns.
Mitigation strategies for CVE-2017-3166 require immediate attention and involve multiple layers of security controls. Organizations should prioritize upgrading to patched versions of Apache Hadoop that address this vulnerability, as the issue affects multiple major release lines. Additionally, administrators should implement strict file permission controls and monitor encryption zone access patterns to detect potential unauthorized file sharing. The recommended approach includes disabling unnecessary world-readable permissions on files within encryption zones and implementing more granular access controls for YARN localization operations. Security teams should also consider implementing network segmentation and monitoring solutions to detect unauthorized file access patterns and ensure that the fix is properly implemented across all cluster nodes.