CVE-2018-18843 in Enterprise Edition
Summary
by MITRE
The Kubernetes integration in GitLab Enterprise Edition 11.x before 11.2.8, 11.3.x before 11.3.9, and 11.4.x before 11.4.4 has SSRF.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 06/13/2023
The vulnerability identified as CVE-2018-18843 represents a server-side request forgery flaw within the Kubernetes integration component of GitLab Enterprise Edition. This issue affects specific versions of GitLab where the Kubernetes integration functionality fails to properly validate and sanitize external requests, creating a pathway for malicious actors to manipulate the system's network communications. The vulnerability resides in the way GitLab processes requests related to Kubernetes cluster management and integration, potentially allowing unauthorized access to internal network resources that should remain isolated from external threats.
The technical implementation of this vulnerability stems from insufficient input validation within the Kubernetes integration module. When GitLab processes requests to communicate with Kubernetes clusters, the system fails to adequately verify the origins and destinations of these requests. This weakness enables attackers to craft malicious requests that can traverse internal network boundaries, potentially accessing sensitive systems, databases, or services that are normally protected by network segmentation. The flaw operates at the application layer where the integration component makes HTTP requests to Kubernetes APIs and other network services without proper validation of the target endpoints. This issue aligns with CWE-918, which specifically addresses server-side request forgery vulnerabilities where applications fail to properly validate external requests.
The operational impact of this vulnerability extends beyond simple network reconnaissance, as it could enable attackers to escalate privileges and gain unauthorized access to internal systems. An attacker exploiting this vulnerability could potentially access Kubernetes cluster credentials, internal databases, or other sensitive infrastructure components that are normally protected by network security controls. The vulnerability affects organizations using GitLab Enterprise Edition in environments where Kubernetes clusters are integrated, particularly those with complex network architectures where internal resources are not adequately isolated. This flaw could be leveraged as part of a broader attack chain, potentially leading to data breaches, system compromise, or denial of service conditions that could disrupt critical development and deployment workflows.
Organizations affected by this vulnerability should prioritize immediate remediation through the application of the vendor-provided security patches that address the SSRF implementation in the Kubernetes integration module. The recommended mitigation strategy involves upgrading to GitLab Enterprise Edition versions 11.2.8, 11.3.9, or 11.4.4, which contain the necessary fixes to validate and sanitize external requests properly. Network segmentation controls should be reviewed to ensure that even if exploitation occurs, the attacker's access remains limited to prevent lateral movement. Additionally, implementing proper input validation and request filtering mechanisms within the application layer can provide defense-in-depth protection against similar vulnerabilities. Security monitoring should be enhanced to detect anomalous network requests originating from the GitLab integration components, as these may indicate exploitation attempts. This vulnerability demonstrates the importance of validating all external communications in integrated platforms and aligns with ATT&CK technique T1190, which covers the exploitation of vulnerabilities in integrated systems to gain unauthorized access to internal resources.