CVE-2023-45821 in Artifact Hub
Summary
by MITRE • 10/25/2023
Artifact Hub is a web-based application that enables finding, installing, and publishing packages and configurations for CNCF projects. During a security audit of Artifact Hub's code base a security researcher identified a bug in which the `registryIsDockerHub` function was only checking that the registry domain had the `docker.io` suffix. Artifact Hub allows providing some Docker credentials that are used to increase the rate limit applied when interacting with the Docker Hub registry API to read publicly available content. Due to the incorrect check described above, it'd be possible to hijack those credentials by purchasing a domain which ends with `docker.io` and deploying a fake OCI registry on it. uses some credentials that only have permissions to read public content available in the Docker Hub. However, even though credentials for private repositories (disabled on `artifacthub.io`) are handled in a different way, other Artifact Hub deployments could have been using them for a different purpose. This issue has been resolved in version `1.16.0`. Users are advised to upgrade. There are no known workarounds for this vulnerability.
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Analysis
by VulDB Data Team • 11/11/2023
The vulnerability identified as CVE-2023-45821 affects Artifact Hub, a web-based application designed for discovering, installing, and publishing packages and configurations for Cloud Native Computing Foundation projects. This security flaw stems from a critical flaw in the `registryIsDockerHub` function implementation that performs inadequate domain validation. The function only verifies that registry domains end with the `docker.io` suffix without proper domain validation mechanisms, creating a significant security risk that could allow credential hijacking attacks.
The technical implementation flaw resides in the insufficient validation logic that fails to properly authenticate registry domains before trusting Docker Hub credentials. This vulnerability specifically targets deployments that utilize Docker Hub credentials for rate limiting purposes when accessing publicly available content. The flaw operates under CWE-20, which describes improper input validation, and represents a classic case of insufficient domain validation where attackers can exploit the wildcard-like matching behavior to deceive the system. The security researcher's discovery revealed that an attacker could purchase a domain ending with `docker.io` and deploy a malicious OCI registry that would be incorrectly accepted as legitimate by the system.
The operational impact of this vulnerability extends beyond simple credential theft, as it could enable attackers to manipulate Artifact Hub's interaction with Docker Hub's API. Even though the credentials in question are intended for reading public content only, the potential for abuse remains significant since these credentials could be used to increase rate limiting thresholds for malicious activities. The vulnerability affects not only the default `artifacthub.io` deployment but also other Artifact Hub installations that might have been using the same credential handling patterns for different purposes. Attackers could potentially leverage this to circumvent rate limiting measures, perform more frequent API calls, or even attempt to access private repositories if the deployments were misconfigured. This issue falls under ATT&CK technique T1566 for credential harvesting and T1071 for application layer protocol usage, representing a sophisticated attack vector that exploits trust relationships in container registry handling.
The vulnerability was addressed in Artifact Hub version 1.16.0 through proper domain validation implementation that ensures complete domain matching rather than simple suffix checking. Organizations using Artifact Hub deployments should immediately upgrade to this version or later to mitigate the risk. Security teams should conduct thorough audits of their Artifact Hub installations to identify any deployments that might be using Docker Hub credentials for purposes beyond simple public content access. The lack of known workarounds means that organizations cannot implement temporary mitigations and must rely entirely on the official patch. This vulnerability demonstrates the critical importance of proper domain validation in security-sensitive applications and highlights how seemingly minor implementation flaws can create significant attack vectors in container registry management systems. The fix implements proper hostname validation that prevents attackers from exploiting the suffix-based matching mechanism to impersonate Docker Hub services.