CVE-2016-0760 in Sentry
Summary
by MITRE
Multiple incomplete blacklist vulnerabilities in Apache Sentry before 1.7.0 allow remote authenticated users to execute arbitrary code via the (1) reflect, (2) reflect2, or (3) java_method Hive builtin functions.
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Analysis
by VulDB Data Team • 03/30/2019
Apache Sentry before version 1.7.0 contained multiple incomplete blacklist vulnerabilities that created significant security risks for Hadoop environments. These vulnerabilities specifically affected the reflect, reflect2, and java_method Hive builtin functions, which were designed to provide reflection capabilities within the Hive query engine. The incomplete blacklists failed to properly restrict or validate user inputs, creating pathways for malicious actors to bypass security controls and execute arbitrary code on systems running vulnerable versions of Apache Sentry.
The technical flaw stemmed from insufficient input validation and sanitization within the Hive builtin functions that handled reflection operations. When authenticated users submitted crafted inputs to these functions, the incomplete blacklists did not adequately filter or reject potentially dangerous code sequences. This vulnerability exploited the trust model within the Sentry authorization system, where legitimate authenticated users could leverage their permissions to escalate privileges and execute unauthorized operations. The vulnerability was particularly dangerous because it allowed remote authenticated users to bypass the intended security boundaries that Sentry was designed to enforce.
The operational impact of CVE-2016-0760 was substantial for organizations relying on Apache Sentry for data access control within Hadoop ecosystems. Attackers could leverage these vulnerabilities to execute arbitrary code on target systems, potentially leading to complete system compromise, data exfiltration, or disruption of critical data processing operations. The remote execution capability meant that attackers did not need physical access to the systems, making the vulnerability particularly attractive for widespread exploitation. Organizations using older versions of Sentry faced increased risk of data breaches and unauthorized access to sensitive information stored within their Hadoop clusters.
The vulnerability aligns with CWE-20: Improper Input Validation and CWE-79: Cross-Site Scripting, as it involved inadequate validation of user-supplied inputs that could be manipulated to execute unintended code. From an ATT&CK perspective, this vulnerability maps to T1059.007: Command and Scripting Interpreter: Python and T1068: Exploitation for Privilege Escalation, as it enabled attackers to execute code through legitimate system interfaces while potentially escalating their privileges within the system. Organizations should have implemented immediate mitigations including upgrading to Apache Sentry version 1.7.0 or later, implementing additional input validation layers, and conducting comprehensive security assessments of their Hadoop environments to identify and remediate similar vulnerabilities. The incident highlighted the critical importance of maintaining up-to-date security controls and implementing defense-in-depth strategies to protect against sophisticated attack vectors targeting data access control systems.