Grafana Cross-Site Scripting Vulnerability Allowing Arbitrary JavaScript Execution

A cross-site scripting (XSS) vulnerability has been identified in Grafana, an open-source monitoring and observability platform. This issue affects Grafana versions 8.0.0-beta1 prior to 8.2.3. The vulnerability allows an attacker to execute arbitrary JavaScript in the context of the victim's browser. Exploitation requires convincing the victim to visit a crafted URL that references a vulnerable page, specifically one that includes the login button in the menu bar. The URL must be designed to exploit AngularJS rendering by incorporating interpolation bindings for AngularJS expressions, which are denoted by double curly braces. When the malicious link is followed, the AngularJS rendering engine executes the embedded JavaScript, potentially leading to unauthorized actions or data exposure.

Impact

Exploitation of this vulnerability allows for cross-site scripting, where an attacker can execute malicious JavaScript in the context of the victim's browser. This could be used to steal session cookies, impersonate the user, or perform actions on behalf of the user.

Reproduction

To reproduce this vulnerability, an unauthenticated user must be convinced to click on a link that leads to a vulnerable Grafana page, such as a dashboard snapshot or an invitation link. The link must be crafted to include a JavaScript payload within the AngularJS interpolation syntax. Once the link is clicked, the injected script will execute, demonstrating the cross-site scripting vulnerability.

Remediation

Users are advised to upgrade Grafana to version 8.2.3 or later. For those unable to upgrade, a reverse proxy can be used to block requests containing the interpolation binding syntax.