CVE-2022-30535 in NGINX Ingress Controller
Summary
by MITRE • 08/04/2022
In versions 2.x before 2.3.0 and all versions of 1.x, An attacker authorized to create or update ingress objects can obtain the secrets available to the NGINX Ingress Controller. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 08/05/2022
The vulnerability identified as CVE-2022-30535 represents a critical security flaw in the NGINX Ingress Controller software that allows authenticated attackers with specific privileges to access sensitive secret information. This issue affects versions 2.x prior to 2.3.0 and all versions within the 1.x release line, making it a widespread concern for organizations utilizing NGINX ingress controllers in their containerized environments. The vulnerability stems from improper handling of secret references within ingress object configurations, creating an information disclosure risk that could potentially compromise the entire ingress controller infrastructure.
The technical root cause of this vulnerability lies in the insecure processing of Kubernetes secret objects when ingress resources are created or updated. When an attacker possesses the authorization to modify ingress objects, they can craft malicious ingress configurations that reference secrets stored within the cluster. The NGINX Ingress Controller fails to properly validate or sanitize these secret references, allowing the controller to expose or leak the contents of these sensitive objects. This flaw operates at the intersection of configuration management and access control, where legitimate administrative privileges are abused to gain unauthorized access to confidential data. The vulnerability aligns with CWE-200, which addresses improper exposure of sensitive information, and specifically demonstrates how insecure object references can lead to information disclosure attacks.
The operational impact of CVE-2022-30535 extends beyond simple information disclosure, as it can potentially enable more sophisticated attacks within the compromised environment. Attackers who exploit this vulnerability can access TLS certificates, API keys, database credentials, and other sensitive information stored as Kubernetes secrets. This access could facilitate lateral movement within the cluster, allow attackers to impersonate services, or provide them with the credentials needed to access external systems. The vulnerability is particularly concerning in multi-tenant environments where different teams or applications share the same ingress controller instance, as it could allow one team to access another team's sensitive configurations and credentials. From an adversary perspective, this vulnerability maps to ATT&CK technique T1552.001, which covers credentials in files, and T1078, which addresses valid accounts, as attackers can leverage legitimate access to ingress objects to extract sensitive information.
Organizations should immediately prioritize updating their NGINX Ingress Controller installations to versions 2.3.0 or later, which contain the necessary patches to address this vulnerability. The remediation process should include comprehensive testing of ingress configurations to ensure compatibility with the updated controller version. Additionally, organizations should implement strict access controls and least privilege principles for ingress object modifications, limiting the number of users or services that can create or update ingress resources. Network segmentation and monitoring solutions should be deployed to detect anomalous ingress configuration changes that might indicate exploitation attempts. Regular security assessments and vulnerability scanning should be conducted to identify any other potential misconfigurations or insecure practices within the ingress controller infrastructure. The fix for this vulnerability demonstrates the critical importance of proper input validation and secure configuration management in containerized environments where ingress controllers serve as the primary entry point for external traffic.