CVE-2022-43572 in Splunk
Summary
by MITRE • 11/05/2022
In Splunk Enterprise versions below 8.2.9, 8.1.12, and 9.0.2, sending a malformed file through the Splunk-to-Splunk (S2S) or HTTP Event Collector (HEC) protocols to an indexer results in a blockage or denial-of-service preventing further indexing.
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Analysis
by VulDB Data Team • 12/05/2022
The vulnerability identified as CVE-2022-43572 represents a critical denial-of-service weakness affecting Splunk Enterprise deployments across multiple version lines including 8.2.8 and below, 8.1.11 and below, and 9.0.1 and below. This flaw specifically targets the Splunk-to-Splunk and HTTP Event Collector protocols, which are fundamental components for data ingestion and communication within Splunk environments. The vulnerability arises from insufficient input validation mechanisms within the indexing process, allowing malicious actors to craft specially formatted data packets that can cause the indexer to become unresponsive or completely block further data processing operations.
The technical exploitation of this vulnerability occurs when malformed data is transmitted through either the S2S protocol or HEC endpoints to a vulnerable Splunk indexer. The flaw manifests as a failure in the parsing and validation logic that processes incoming data streams, causing the indexer to either hang during processing or terminate its indexing operations entirely. This behavior creates a cascading effect where legitimate data ingestion is prevented, effectively rendering the affected indexer incapable of processing new events until manual intervention occurs through service restarts or system reboot procedures. The vulnerability is particularly concerning because it can be triggered through legitimate data ingestion points, making it difficult to distinguish between malicious and benign traffic patterns.
From an operational impact perspective, this vulnerability presents significant risks to organizations relying on Splunk for critical monitoring and security operations. The denial-of-service condition can disrupt real-time threat detection, log analysis, and operational monitoring capabilities that depend on continuous data ingestion. Security teams may experience delayed incident response times as their Splunk infrastructure becomes unavailable, potentially allowing security threats to go undetected during the service disruption period. The vulnerability also affects business continuity operations where Splunk serves as a central repository for operational data, system logs, and performance metrics that support decision-making processes across multiple departments.
The vulnerability aligns with CWE-400, which addresses "Uncontrolled Resource Consumption," and demonstrates characteristics consistent with resource exhaustion attacks that target parsing and validation functions. From an ATT&CK framework perspective, this vulnerability maps to T1499.004, "Endpoint Denial of Service," and potentially T1566.001, "Phishing via Social Engineering," if attackers leverage this weakness as part of a broader attack chain. Organizations should implement immediate mitigations including upgrading to patched versions of Splunk Enterprise, implementing network segmentation to limit access to S2S and HEC endpoints, and deploying intrusion detection systems to monitor for anomalous data patterns that might indicate exploitation attempts.
Organizations should prioritize patching their Splunk Enterprise installations to versions 8.2.9, 8.1.12, or 9.0.2, which contain the necessary fixes for this vulnerability. Additionally, implementing rate limiting and input validation controls at network boundaries can help reduce the attack surface while patches are deployed. Security monitoring should be enhanced to detect unusual data ingestion patterns that might indicate exploitation attempts, and regular vulnerability assessments should be conducted to identify other potential weaknesses in the Splunk infrastructure configuration. The remediation process should include thorough testing of patched environments to ensure that the fixes do not introduce compatibility issues with existing Splunk applications and data processing pipelines.