CVE-2022-31035 is a cross-site scripting (XSS) vulnerability identified in Argo CD, a popular declarative GitOps continuous delivery tool for Kubernetes environments. The vulnerability affects all Argo CD versions starting from v1.0.0 up to but not including patched versions v2.1.16, v2.2.10, v2.3.5, and v2.4.1. The core issue stems from improper neutralization of input during web page generation (CWE-79), allowing a malicious actor to inject a `javascript:` link into the Argo CD user interface. When a victim user clicks this injected link, the embedded script executes with the victim's privileges, which can be as high as administrative rights. This execution capability enables the attacker to perform any action accessible via the UI or API, including creating, modifying, or deleting Kubernetes resources managed by Argo CD. The vulnerability arises due to insufficient sanitization of user-controllable input that is rendered in the web interface, enabling script injection. No fully safe workarounds exist other than upgrading to the patched versions. Although no known exploits have been reported in the wild to date, the potential for abuse is significant given the elevated permissions and control over Kubernetes resources that could be gained through this vector. The vulnerability was publicly disclosed on June 27, 2022, and is classified as medium severity by the vendor, though it carries substantial risk in environments where Argo CD is used to manage critical infrastructure.

For European organizations, the impact of this vulnerability can be severe, particularly for those relying on Argo CD for Kubernetes continuous delivery pipelines. Successful exploitation can lead to unauthorized administrative control over Kubernetes clusters, enabling attackers to manipulate workloads, deploy malicious containers, exfiltrate sensitive data, or disrupt service availability. This can compromise the confidentiality, integrity, and availability of critical applications and data. Given the widespread adoption of Kubernetes and GitOps methodologies in Europe’s technology, finance, manufacturing, and public sectors, exploitation could result in operational downtime, regulatory non-compliance (e.g., GDPR breaches), and reputational damage. The attack vector requires user interaction (clicking a malicious link), but since Argo CD users often have elevated privileges, the consequences of a successful attack are amplified. The lack of known exploits in the wild suggests limited active targeting so far, but the vulnerability’s nature makes it a high-value target for attackers aiming to pivot within Kubernetes environments.

The primary and only fully effective mitigation is to upgrade Argo CD installations to the patched versions: v2.1.16, v2.2.10, v2.3.5, or v2.4.1 or later. Organizations should prioritize this upgrade in their Kubernetes management pipelines. Additionally, to reduce risk before patching, organizations can implement strict role-based access control (RBAC) within Argo CD to limit the number of users with administrative privileges, minimizing the impact of a compromised user session. Monitoring and alerting on unusual UI interactions or API calls can help detect exploitation attempts. Employing web application firewalls (WAFs) with custom rules to detect and block suspicious `javascript:` URI schemes in HTTP requests to the Argo CD UI may provide temporary mitigation, though this is not foolproof. Security teams should also educate users about the risks of clicking untrusted links within the Argo CD interface. Finally, regular security audits of Kubernetes configurations and continuous delivery pipelines can help identify and remediate potential attack vectors related to this vulnerability.