CVE-2016-6809 in Tika
Summary
by MITRE
Apache Tika before 1.14 allows Java code execution for serialized objects embedded in MATLAB files. The issue exists because Tika invokes JMatIO to do native deserialization.
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Analysis
by VulDB Data Team • 05/30/2019
Apache Tika version 1.14 and earlier contained a critical vulnerability that enabled remote Java code execution through maliciously crafted MATLAB files. This vulnerability stems from Tika's reliance on the JMatIO library for processing MATLAB file formats, which performs unsafe deserialization operations without proper input validation. The flaw occurs when Tika processes MATLAB files that contain serialized Java objects, allowing attackers to inject malicious code that executes within the Tika processing context.
The technical exploitation of this vulnerability follows a well-defined pattern that aligns with common Java deserialization attack vectors. When Tika encounters a MATLAB file containing serialized objects, it delegates processing to JMatIO which attempts to deserialize these objects without adequate security checks. This creates an environment where attacker-controlled serialized data can trigger arbitrary code execution on the system running Tika. The vulnerability represents a classic deserialization flaw that can be leveraged for remote code execution, privilege escalation, and system compromise.
From an operational perspective, this vulnerability poses significant risks to organizations using Tika for document processing, content analysis, or file ingestion services. Systems that process untrusted documents, such as email servers, document management platforms, or content delivery networks, become vulnerable to remote exploitation. The impact extends beyond simple code execution to potential full system compromise, especially when Tika runs with elevated privileges or in environments where it can access sensitive resources. This vulnerability can be exploited through various attack vectors including web applications, file upload mechanisms, or automated document processing pipelines.
The security implications of CVE-2016-6809 align with CWE-502 which specifically addresses deserialization of untrusted data. This vulnerability also maps to several ATT&CK techniques including T1059.007 for scripting and T1203 for exploitation of remote services. Organizations should prioritize immediate patching to Tika version 1.14 or later, which addresses the deserialization issue through improved input validation and secure processing of serialized objects. Additional mitigations include implementing network segmentation, restricting file upload capabilities, and deploying application firewalls to monitor and block suspicious deserialization attempts. Security teams should also consider implementing runtime monitoring to detect anomalous deserialization activities that may indicate exploitation attempts.