CVE-2022-21702 is a Cross-site Scripting (XSS) vulnerability affecting Grafana, an open-source platform widely used for monitoring and observability. The vulnerability arises due to improper neutralization of input during web page generation (CWE-79), allowing an attacker to inject malicious HTML content through the Grafana datasource or plugin proxy. Specifically, if a Grafana HTTP-based datasource or app plugin is configured with 'Server' as the access mode and points to a URL controlled by an attacker, the attacker can craft a malicious link that, when clicked by an authenticated Grafana user, executes arbitrary HTML/JavaScript code in the context of the Grafana web application. This can happen in three scenarios: 1) the attacker controls the HTTP server serving the datasource URL, 2) the attacker controls the HTTP server serving the plugin URL, or 3) the attacker can navigate an authenticated user to a compromised plugin via a crafted link. Exploitation requires that the user is authenticated to the Grafana instance and clicks on the malicious link. The affected Grafana versions include all versions from 2.0.0-beta1 up to but not including 7.5.15, and from 8.0.0 up to but not including 8.3.5. No known workarounds exist, and users are advised to update to patched versions. Although no known exploits are currently observed in the wild, the vulnerability poses a risk due to the potential for session hijacking, credential theft, or execution of arbitrary actions within the Grafana environment by leveraging the victim's authenticated session.

For European organizations, the impact of this vulnerability can be significant, especially for those relying heavily on Grafana for monitoring critical infrastructure, IT systems, and business applications. Successful exploitation could lead to unauthorized access to sensitive monitoring data, manipulation of dashboards, or execution of malicious scripts that compromise user sessions and credentials. This could result in data leakage, disruption of monitoring capabilities, and potential lateral movement within the network. Given that Grafana is often integrated with various data sources and plugins, the attack surface is broad, and the compromise of a single datasource or plugin could cascade into wider organizational impact. Additionally, organizations in sectors such as finance, energy, healthcare, and government, which rely on real-time monitoring and observability, could face operational disruptions and regulatory compliance issues if monitoring data integrity or availability is compromised.

1. Immediate upgrade of all affected Grafana instances to the latest patched versions beyond 7.5.15 or 8.3.5 as applicable. 2. Review and restrict the configuration of HTTP-based datasources and app plugins to ensure that only trusted URLs and servers are used, minimizing exposure to attacker-controlled endpoints. 3. Implement strict network segmentation and firewall rules to limit outbound connections from Grafana servers to only trusted data sources and plugin endpoints. 4. Educate users to avoid clicking on unsolicited or suspicious links related to Grafana dashboards or plugins, especially those received via email or messaging platforms. 5. Monitor Grafana logs for unusual access patterns or unexpected datasource/plugin configurations that could indicate attempted exploitation. 6. Employ Content Security Policy (CSP) headers and other web application security controls to reduce the impact of potential XSS attacks. 7. Regularly audit and validate installed plugins and datasources to ensure they come from trusted sources and have not been tampered with. 8. Consider implementing multi-factor authentication (MFA) for Grafana users to reduce the risk of session hijacking.