CVE-2018-1338 in Tika
Summary
by MITRE
A carefully crafted (or fuzzed) file can trigger an infinite loop in Apache Tika's BPGParser in versions of Apache Tika before 1.18.
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Analysis
by VulDB Data Team • 03/07/2023
The vulnerability identified as CVE-2018-1338 represents a critical denial of service flaw within Apache Tika's BPGParser component, which processes Binary Pixel Graphics format files. This issue affects Apache Tika versions prior to 1.18 and stems from inadequate input validation mechanisms within the parser's code structure. The flaw manifests when processing specifically crafted or fuzzed BPG files that contain malformed data structures designed to exploit the parser's handling logic. The vulnerability operates through a control flow manipulation that causes the parser to enter an infinite loop during file processing operations, effectively consuming system resources and rendering the application unresponsive.
The technical implementation of this vulnerability resides in the BPGParser's algorithmic processing of image file headers and data segments. When the parser encounters a malformed BPG file containing specific byte sequences or structural anomalies, the parsing logic fails to properly validate loop termination conditions. This results in a scenario where the parser's internal loop continues indefinitely without proper exit conditions, causing the system to allocate continuous CPU cycles and memory resources. The vulnerability maps directly to CWE-835, which defines the weakness of an infinite loop or infinite recursion, and demonstrates how improper input validation can lead to resource exhaustion attacks. The flaw operates at the application layer within the Apache Tika framework, specifically targeting the image parsing functionality that handles Binary Pixel Graphics file formats.
The operational impact of this vulnerability extends beyond simple service disruption, as it can be exploited to cause significant system resource exhaustion across multiple deployment scenarios. An attacker could potentially submit malicious BPG files to any system running vulnerable Apache Tika versions, leading to complete service unavailability for legitimate users. This makes the vulnerability particularly dangerous in web applications, content management systems, or document processing services that rely on Apache Tika for file analysis. The infinite loop condition can cause memory leaks, CPU saturation, and overall system degradation that may require manual intervention to resolve, potentially leading to extended downtime and service interruption. The attack vector is relatively simple to execute, requiring only the delivery of a crafted file to the vulnerable system, making it accessible to threat actors with minimal technical expertise.
Organizations should implement immediate mitigation strategies including updating to Apache Tika version 1.18 or later, which contains the necessary patches to address the infinite loop condition in BPGParser. Network-based defenses such as file type validation, content scanning, and sandboxed processing environments can provide additional layers of protection while awaiting the official updates. System administrators should also consider implementing resource limits and monitoring mechanisms to detect unusual CPU or memory consumption patterns that might indicate exploitation attempts. The vulnerability aligns with ATT&CK technique T1499.004, which covers network denial of service attacks, and represents a classic example of how malformed input can be leveraged to create resource exhaustion conditions. Security teams should also review their file processing pipelines to ensure that all third-party libraries and components are kept up to date with the latest security patches to prevent similar vulnerabilities from being exploited in their environments.