CVE-2023-3637 in openstack-neutron
Summary
by MITRE • 07/25/2023
An uncontrolled resource consumption flaw was found in openstack-neutron. This flaw allows a remote authenticated user to query a list of security groups for an invalid project. This issue creates resources that are unconstrained by the user's quota. If a malicious user were to submit a significant number of requests, this could lead to a denial of service.
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Analysis
by VulDB Data Team • 08/30/2025
The vulnerability identified as CVE-2023-3637 resides within the openstack-neutron component, specifically targeting the security group management functionality. This flaw represents a classic resource exhaustion issue that can be exploited by authenticated attackers to consume system resources beyond normal operational limits. The vulnerability manifests when an authenticated user submits queries for security group lists associated with invalid project identifiers, creating a scenario where the system processes requests without proper resource constraints. This uncontrolled resource consumption directly violates the principle of resource management and can severely impact system availability and performance. The flaw exists in the validation logic that should normally restrict access to security groups based on project boundaries and user permissions, yet fails to properly validate project identifiers before processing requests.
From a technical perspective, the vulnerability operates by bypassing normal access controls that would typically enforce quota limitations and project boundaries. When a user submits a query for security groups associated with a non-existent or invalid project, the neutron service continues to process these requests without implementing proper resource limits. This processing creates internal data structures and memory allocations that accumulate over time, consuming system resources such as memory, CPU cycles, and database connections. The flaw essentially allows for unlimited resource consumption by a single authenticated user, as there are no mechanisms in place to prevent the accumulation of these unconstrained resources. This behavior aligns with CWE-400, which categorizes uncontrolled resource consumption as a significant security weakness that can lead to denial of service conditions.
The operational impact of this vulnerability extends beyond simple resource exhaustion, creating cascading effects throughout the OpenStack environment. A malicious actor could systematically submit thousands of requests for invalid projects, causing memory leaks, database connection exhaustion, and overall system degradation. The service may become unresponsive to legitimate user requests, as system resources become consumed by the malicious activity. This vulnerability particularly affects cloud environments where neutron services handle numerous security group operations, as the resource consumption can quickly overwhelm system capacity and lead to complete service disruption. The impact is amplified in multi-tenant environments where a single compromised account could potentially affect the entire cloud infrastructure.
Mitigation strategies for CVE-2023-3637 should focus on implementing proper input validation and resource limiting mechanisms within the neutron service. The primary fix involves strengthening the validation logic to reject queries for invalid project identifiers before resource allocation occurs, ensuring that all requests are properly authenticated and authorized before processing. Organizations should implement rate limiting and quota enforcement mechanisms that prevent a single user from consuming excessive system resources, particularly for operations that involve security group queries. Additionally, monitoring and alerting systems should be configured to detect unusual patterns of security group requests that may indicate exploitation attempts. These measures align with ATT&CK technique T1499.004, which involves resource exhaustion attacks targeting availability. The fix should also include implementing proper logging and auditing of security group operations to detect and respond to potential exploitation attempts. Organizations should consider implementing automated response mechanisms that can detect and mitigate resource exhaustion attacks in real-time, protecting the overall stability and availability of their OpenStack deployments.