High-Severity Flaw in Argo CD is Information Leak Risk
A high-severity security vulnerability in Argo CD could allow an attacker to access sensitive information from target applications.
Argo CD, a popular open-source Continuous Delivery (CD) tool for Kubernetes, is used to monitor running applications and compares their live state, helping administrators synchronize applications with their desired state.
Tracked as CVE-2022-24348 (CVSS score of 7.7), the vulnerability is a path traversal bug that allows an attacker to load a Kubernetes Helm Chart YAML file and gain access to other application’s data. Helm charts are YAML files containing different fields that embed resources and configurations required for application deployment.
Kubernetes Helm chart files, which are used when building a new deployment pipeline, contain metadata and information necessary for the deployment, as well as the ability to update the cloud configuration.
The vulnerability allows an attacker to pass arbitrary values files to Helm charts or to craft “special Helm chart packages containing value files that are actually symbolic links, pointing to arbitrary files outside the repository’s root directory,” according an advisory from Argo CD.
The platform’s maintainers note that an attacker looking to exploit the vulnerability must have permissions to create or update applications, and also needs to know or guess “the full path to a file containing valid YAML.”
Thus, the attacker can “create a malicious Helm chart to consume that YAML as values files, thereby gaining access to data they would otherwise have no access to.” Impact, the team says, becomes critical if sensitive or confidential data exist in the environment.
Apiiro, a third-party company that discovered the security issue, warns successful exploitation could allow an attacker to read or steal “secrets, tokens, and other sensitive information residing on other applications.”
The weakness has been known to the development team since 2019, when an anti-path-traversal mechanism was added to the CD. However, the vulnerability exists because of an error in the control.
The patch for this vulnerability was included in the Argo CD releases v2.3.0, v2.2.4, and v2.1.9. The fix prevents “value files outside the repository root.”
Argo CD users are advised to update to a patch version of the platform as soon as possible as no workarounds are availble for this vulnerability exist.