CVE-2018-7432 in Splunk
Summary
by MITRE
Splunk Enterprise 6.2.x before 6.2.14, 6.3.x before 6.3.10, 6.4.x before 6.4.7, and 6.5.x before 6.5.3; and Splunk Light before 6.6.0 allow remote attackers to cause a denial of service via a crafted HTTP request.
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Analysis
by VulDB Data Team • 05/30/2023
The vulnerability identified as CVE-2018-7432 represents a denial of service weakness affecting multiple versions of Splunk Enterprise and Splunk Light products. This issue stems from insufficient input validation within the HTTP request processing mechanism of these Splunk implementations. The flaw allows remote attackers to craft specifically formatted HTTP requests that can trigger unexpected behavior in the application's processing pipeline, ultimately leading to system resource exhaustion or complete service unavailability. The vulnerability impacts versions spanning from 6.2.x through 6.5.x releases, as well as Splunk Light prior to version 6.6.0, indicating a prolonged period of exposure across multiple product lines.
The technical nature of this vulnerability falls under CWE-400, which specifically addresses "Uncontrolled Resource Consumption," and more broadly relates to CWE-122, "Heap-based Buffer Overflow" or similar resource management issues. The flaw manifests when the Splunk application fails to properly validate or sanitize incoming HTTP requests before processing them through its internal request handling framework. Attackers can exploit this by sending maliciously crafted requests that cause the application to consume excessive system resources or enter an unstable state. The HTTP request processing components appear to lack adequate bounds checking or input sanitization, allowing crafted payloads to trigger memory allocation issues or infinite loop conditions that exhaust available processing power or memory resources.
The operational impact of CVE-2018-7432 extends beyond simple service disruption, as it can effectively render Splunk instances unusable for critical log management and security monitoring operations. Organizations relying on Splunk for security information and event management (SIEM) capabilities face significant risk when this vulnerability is exploited, as the denial of service can interrupt real-time threat detection, log analysis, and incident response workflows. The remote nature of the attack means that adversaries can exploit this vulnerability from outside the network perimeter, potentially affecting organizations that have Splunk instances exposed to the internet or those with insufficient network segmentation. This vulnerability particularly affects organizations in sectors where continuous monitoring is critical, such as financial services, healthcare, and government agencies, where even brief service interruptions can have severe operational consequences.
Mitigation strategies for CVE-2018-7432 should prioritize immediate patching of affected Splunk installations to versions 6.2.14, 6.3.10, 6.4.7, 6.5.3, and 6.6.0 respectively, as these releases contain the necessary code fixes to address the input validation issues. Network administrators should implement additional defensive measures including rate limiting on HTTP requests, implementing web application firewalls to filter suspicious traffic patterns, and establishing monitoring alerts for unusual resource consumption patterns that might indicate exploitation attempts. Organizations should also consider implementing network segmentation to limit exposure of Splunk instances to untrusted networks and ensure that only necessary ports are accessible from external networks. The vulnerability aligns with ATT&CK technique T1499.004, "Endpoint Denial of Service," and represents a classic example of how insufficient input validation can lead to resource exhaustion attacks that compromise system availability and operational continuity.