CVE-2021-47713 in GraphQL
Summary
by MITRE • 12/23/2025
Hasura GraphQL 1.3.3 contains a denial of service vulnerability that allows attackers to overwhelm the service by crafting malicious GraphQL queries with excessive nested fields. Attackers can send repeated requests with extremely long query strings and multiple threads to consume server resources and potentially crash the GraphQL endpoint.
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Analysis
by VulDB Data Team • 12/23/2025
The vulnerability identified as CVE-2021-47713 affects Hasura GraphQL Engine version 1.3.3 and represents a significant denial of service weakness that can be exploited through carefully crafted GraphQL query structures. This vulnerability stems from insufficient input validation and resource management within the GraphQL query processing engine, allowing malicious actors to construct queries with excessive nested fields that can overwhelm system resources. The flaw specifically targets the query parsing and execution mechanisms, creating a scenario where legitimate service operations become disrupted due to resource exhaustion caused by malformed query constructions.
The technical implementation of this vulnerability exploits the inherent complexity of GraphQL query parsing where nested fields can create exponential processing requirements. When an attacker submits a GraphQL query containing deeply nested fields with repetitive structures, the Hasura engine must recursively process each level of nesting, leading to increased memory consumption and CPU utilization. The vulnerability is particularly dangerous because it can be amplified through multiple concurrent threads and repeated requests, creating a resource exhaustion scenario that can effectively crash the GraphQL endpoint. This type of attack pattern aligns with CWE-400, which categorizes unchecked resource consumption as a critical weakness in software systems.
The operational impact of CVE-2021-47713 extends beyond simple service disruption to potentially compromise the entire application availability and data integrity. Organizations relying on Hasura GraphQL for critical business operations face significant risk of extended downtime, especially when attackers leverage automated tools to generate massive query loads. The vulnerability can be particularly devastating in cloud environments where resources are shared and excessive consumption can impact neighboring services. Additionally, the attack vector can be difficult to distinguish from legitimate high-complexity queries, making detection and mitigation challenging for security operations teams.
Mitigation strategies for this vulnerability should include implementing comprehensive query complexity analysis and resource limiting mechanisms within the Hasura GraphQL engine configuration. Organizations should establish strict limits on query depth and field count to prevent excessive nesting patterns from being processed. The implementation of rate limiting and request throttling controls can help prevent abuse through multiple concurrent connections. Security measures should also incorporate monitoring and alerting for unusual query patterns that exceed predefined thresholds. According to ATT&CK framework, this vulnerability represents a denial of service attack pattern categorized under T1499, which includes techniques for depleting system resources through various means. Regular updates and patch management should be prioritized to ensure that the Hasura GraphQL engine operates on versions that have addressed this specific resource exhaustion weakness.