CVE-2024-52979 is a vulnerability classified under CWE-400 (Uncontrolled Resource Consumption) affecting Elastic's Elasticsearch versions 7.17.0 and 8.0.0. The issue arises when Elasticsearch evaluates search templates that include specifically crafted Mustache functions. Mustache is a logic-less templating language used within Elasticsearch to dynamically generate search queries. An attacker can exploit this vulnerability by submitting maliciously designed search templates that cause excessive resource consumption during the template evaluation process. This resource exhaustion can overwhelm the Elasticsearch node, leading to a Denial of Service (DoS) condition by crashing the node or severely degrading its performance. The vulnerability requires network access (AV:N), low attack complexity (AC:L), and privileges (PR:L), but does not require user interaction (UI:N). The scope is unchanged (S:U), and the impact is limited to availability (A:H) without affecting confidentiality or integrity. The CVSS 3.1 base score is 6.5, indicating a medium severity level. No known exploits are currently reported in the wild, and no patches have been linked yet. This vulnerability is particularly concerning for environments where Elasticsearch is exposed to users or systems that can submit search templates, especially in multi-tenant or externally accessible deployments. The uncontrolled resource consumption can lead to service disruption, impacting applications and services relying on Elasticsearch for search and analytics functionality.

For European organizations, the impact of CVE-2024-52979 can be significant, especially for those relying heavily on Elasticsearch for critical business operations such as e-commerce search, log analytics, and real-time data processing. A successful exploitation can cause Elasticsearch nodes to crash, resulting in downtime and loss of service availability. This can disrupt business continuity, degrade customer experience, and potentially lead to financial losses. Organizations in sectors such as finance, telecommunications, and public services, which often use Elasticsearch for monitoring and analytics, may face operational risks. Additionally, the requirement for low privileges means that insider threats or compromised internal accounts could exploit this vulnerability. Given that the vulnerability does not affect confidentiality or integrity, data breaches are unlikely, but service outages can indirectly affect compliance with regulations like GDPR if service availability impacts data processing obligations. The absence of known exploits in the wild suggests a window for proactive mitigation before widespread attacks occur.

1. Restrict access to Elasticsearch nodes to trusted internal networks and authenticated users only, minimizing exposure to untrusted sources that could submit malicious search templates. 2. Implement strict role-based access control (RBAC) to limit which users or services can submit or modify search templates, especially those using Mustache functions. 3. Monitor Elasticsearch logs and metrics for unusual spikes in resource consumption or frequent crashes that may indicate exploitation attempts. 4. Employ rate limiting or request throttling on search template submissions to prevent abuse. 5. Use application-layer firewalls or API gateways to validate and sanitize incoming search templates before they reach Elasticsearch. 6. Stay updated with Elastic’s security advisories and apply patches promptly once available. 7. Consider deploying Elasticsearch clusters with redundancy and failover capabilities to minimize downtime in case of node crashes. 8. Conduct internal audits of search templates in use to identify and remove or refactor any that could be vulnerable to resource exhaustion. These measures go beyond generic advice by focusing on access control, monitoring, and proactive template management specific to the nature of this vulnerability.