CVE-2023-45822 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 a default unsafe rego built-in was allowed to be used when defining authorization policies. Artifact Hub includes a fine-grained authorization mechanism that allows organizations to define what actions can be performed by their members. It is based on customizable authorization policies that are enforced by the `Open Policy Agent`. Policies are written using `rego` and their data files are expected to be json documents. By default, `rego` allows policies to make HTTP requests, which can be abused to send requests to internal resources and forward the responses to an external entity. In the context of Artifact Hub, this capability should have been disabled. 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-2023-45822 affects Artifact Hub, a web-based platform designed for discovering, installing, and publishing packages related to Cloud Native Computing Foundation projects. This security flaw resides within Artifact Hub's authorization mechanism that relies on Open Policy Agent for enforcing access controls. The system employs rego policies to define what actions users can perform, with policies written in rego language and data files formatted as json documents. The core issue emerges from the improper configuration of rego built-in functions that should have been restricted but remained enabled by default.
The technical flaw represents a critical authorization bypass vulnerability where the default unsafe rego built-in function was permitted to execute during policy evaluation. This specific rego built-in allows policies to make HTTP requests to arbitrary endpoints, creating a pathway for attackers to leverage the authorization system against internal network resources. The vulnerability stems from the default rego configuration that enables network connectivity capabilities within policy enforcement, which should have been disabled in the context of Artifact Hub's security model. This misconfiguration allows malicious actors to craft rego policies that can reach internal services, potentially exfiltrating sensitive data or performing unauthorized operations on behalf of legitimate users.
The operational impact of this vulnerability is severe as it undermines the fundamental security model of Artifact Hub's authorization system. Attackers could exploit this flaw to access internal resources that should remain protected from external or even internal unauthorized access. The vulnerability enables potential data exfiltration, privilege escalation, and unauthorized access to sensitive information within the organization's infrastructure. Since Artifact Hub operates as a central repository for CNCF projects, the compromise could affect multiple projects and their associated configurations, potentially leading to widespread security implications across an organization's cloud native ecosystem. The vulnerability also creates a persistent risk as it allows attackers to maintain access through crafted policies that can be executed within the authorization framework.
This vulnerability aligns with CWE-284 Access Control Issues and specifically relates to CWE-1035 Improper Control of Generation of Code, where unsafe code generation capabilities are exposed in policy evaluation systems. The flaw also maps to ATT&CK technique T1078 Valid Accounts, as it allows for unauthorized access through legitimate user accounts by leveraging the authorization policy system. Additionally, it corresponds to T1566 Phishing and T1046 Network Service Scanning, as attackers could use this capability to discover and interact with internal services. Organizations using Artifact Hub versions prior to 1.16.0 face significant risk exposure, particularly those with complex authorization requirements or internal network segmentation. The vulnerability represents a critical configuration oversight in the security hardening of policy enforcement systems, where network capabilities should have been explicitly disabled to prevent lateral movement and data access violations.
The remediation involves upgrading to Artifact Hub version 1.16.0, which properly disables the unsafe rego built-in functions that were previously enabled by default. This upgrade addresses the root cause by ensuring that policy evaluation environments do not have unintended network capabilities that could be exploited. Organizations should also conduct comprehensive security reviews of their existing rego policies to identify any that may have been leveraging the unsafe functionality. Security teams should implement monitoring for unauthorized policy changes and establish proper configuration management procedures to prevent similar issues in other systems utilizing Open Policy Agent or similar policy engines. The fix demonstrates the importance of principle of least privilege in security architecture, ensuring that policy evaluation environments operate with minimal required capabilities to prevent exploitation of authorization bypass vulnerabilities.