CVE-2023-22736 Explained : Impact and Mitigation

This CVE identifies a vulnerability in the argo-cd Controller that allows for the reconciliation of applications outside configured namespaces when sharding is enabled.

Understanding CVE-2023-22736

This vulnerability in Argo CD, a GitOps continuous delivery tool for Kubernetes, could potentially lead to an authorization bypass bug, enabling a malicious user to deploy applications outside the configured allowed namespaces.

What is CVE-2023-22736?

The vulnerability arises in versions starting from 2.5.0-rc1 up to 2.5.8, as well as version 2.6.0-rc4, allowing malicious users to deploy applications in namespaces not specified by the allowed patterns when sharding is enabled on the Application controller.

The Impact of CVE-2023-22736

This vulnerability could lead to unauthorized deployment of applications, potentially compromising the security and integrity of the Kubernetes environment where Argo CD is in use.

Technical Details of CVE-2023-22736

Argo CD versions affected by this vulnerability include those from 2.5.0-rc1 to 2.5.8 and version 2.6.0-rc4. The vulnerability allows for an authorization bypass, enabling users to deploy applications outside the configured namespaces under certain conditions.

Vulnerability Description

The vulnerability arises due to a lack of enforcement of the specified list of patterns when reconciling applications if sharding is enabled.

Affected Systems and Versions

Vendor: argoproj Affected Product: argo-cd Vulnerable Versions:

= 2.5.0-rc1, < 2.5.8

= 2.6.0-rc4, < 2.6.0-rc5

Exploitation Mechanism

The bug requires the malicious user to trigger an update operation on the application resource to cause reconciliation of applications in out-of-bounds namespaces.

Mitigation and Prevention

To address CVE-2023-22736, immediate steps should be taken to mitigate the risk and prevent exploitation of the vulnerability.

Immediate Steps to Take

Update to patched versions 2.5.8 and 2.6.0-rc5 to address the vulnerability.
Run only one replica of the Application controller to prevent exploitation.
Ensure AppProjects' sourceNamespaces are restricted within the configured Application namespaces to prevent unauthorized deployment.

Long-Term Security Practices

Regularly update software to apply security patches promptly and follow best practices for secure Kubernetes deployment.

Patching and Updates

Ensure all Argo CD instances are updated to versions 2.5.8 and 2.6.0-rc5, where the vulnerability has been patched, to mitigate the risk of exploitation.