CVE-2024-52979 in Elasticsearch
Summary
by MITRE • 05/01/2025
Uncontrolled Resource Consumption in Elasticsearch while evaluating specifically crafted search templates with Mustache functions can lead to Denial of Service by causing the Elasticsearch node to crash.
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Analysis
by VulDB Data Team • 10/03/2025
The vulnerability identified as CVE-2024-52979 represents a critical resource consumption issue within the Elasticsearch distributed search and analytics engine. This flaw specifically manifests when Elasticsearch processes search templates that incorporate Mustache templating functions, creating a scenario where maliciously crafted input can trigger excessive resource utilization. The vulnerability falls under the category of uncontrolled resource consumption, which is classified as CWE-400 in the Common Weakness Enumeration catalog, indicating a direct risk of system instability and service disruption. The issue affects Elasticsearch nodes that handle template-based search operations, particularly those involving complex Mustache expressions that require significant computational resources to evaluate.
The technical mechanism behind this vulnerability involves the evaluation process of Mustache template functions within Elasticsearch's search template engine. When a specially crafted search template containing recursive or deeply nested Mustache expressions is processed, the system's resource allocation becomes increasingly strained as it attempts to resolve template variables and execute the associated logic. The Mustache templating engine, while powerful for dynamic content generation, becomes susceptible to exponential resource consumption when handling maliciously constructed templates. This occurs because the template evaluation process lacks proper bounds checking and resource limiting mechanisms, allowing attackers to craft inputs that cause the system to consume excessive memory and CPU resources during template processing. The vulnerability is particularly dangerous because it can be exploited through standard search operations, making it accessible to users with basic search permissions.
The operational impact of CVE-2024-52979 extends beyond simple performance degradation to full system denial of service conditions. When exploited, the vulnerability can cause individual Elasticsearch nodes to become unresponsive, leading to complete service disruption for applications relying on the search platform. The resource exhaustion typically manifests as memory allocation failures, process timeouts, or complete node crashes that require manual intervention and system restarts. Organizations utilizing Elasticsearch for critical operations face significant business continuity risks, as the vulnerability can be exploited remotely without requiring elevated privileges. The attack surface is particularly broad since many Elasticsearch deployments allow external access to search endpoints, and the vulnerability can be triggered through common search template operations that are frequently used in production environments. This makes the vulnerability highly attractive to threat actors seeking to disrupt services.
Mitigation strategies for CVE-2024-52979 should focus on both immediate protective measures and long-term architectural improvements. Organizations should implement strict resource limits and timeouts for template evaluation processes, configuring Elasticsearch to reject templates exceeding predetermined complexity thresholds. The implementation of proper input validation and sanitization for search templates can prevent malicious constructs from being processed, while rate limiting mechanisms can help reduce the impact of potential attacks. Security teams should also consider implementing monitoring solutions that can detect unusual resource consumption patterns and alert administrators to potential exploitation attempts. From a defensive perspective, this vulnerability aligns with ATT&CK technique T1499.004 for resource exhaustion attacks, making it particularly relevant for organizations implementing adversarial threat modeling. The most effective immediate solution involves applying available patches from Elasticsearch vendors, while longer-term strategies should include comprehensive template validation policies and regular security assessments of search template usage patterns.