CVE-2025-6023: Grafana OSS Open Redirect XSS Vulnerability

CVE-2025-6023 Overview

An open redirect vulnerability has been identified in Grafana OSS that can be exploited to achieve Cross-Site Scripting (XSS) attacks. The vulnerability was introduced in Grafana v11.5.0 and allows attackers to chain open redirect behavior with path traversal vulnerabilities to execute arbitrary JavaScript in the context of a victim's browser session.

This vulnerability poses a significant risk to organizations using affected Grafana versions, as successful exploitation could lead to session hijacking, credential theft, and unauthorized access to sensitive monitoring data and dashboards.

Critical Impact

Attackers can chain the open redirect with path traversal to achieve XSS, potentially compromising user sessions and accessing sensitive monitoring infrastructure data.

Affected Products

• Grafana OSS versions 11.5.0 through 11.5.5
• Grafana OSS versions 11.6.0 through 11.6.2
• Grafana OSS versions 12.0.0 through 12.0.1

Discovery Timeline

• 2025-07-17 - Grafana releases security patches addressing the vulnerability
• 2025-07-18 - CVE CVE-2025-6023 published to NVD
• 2025-07-22 - Last updated in NVD database

Technical Details for CVE-2025-6023

Vulnerability Analysis

This vulnerability combines two attack techniques: open redirect and path traversal, which together enable XSS attacks against Grafana users. Open redirect vulnerabilities occur when an application accepts user-controlled input that specifies a URL for redirection without proper validation. In this case, the open redirect functionality in Grafana can be manipulated to redirect users to attacker-controlled resources or, more critically, to internal paths that expose XSS attack surfaces.

The vulnerability is classified under CWE-79 (Improper Neutralization of Input During Web Page Generation), indicating that user-supplied data is not properly sanitized before being reflected in the application's output. When combined with path traversal techniques, attackers can bypass security controls and inject malicious scripts into the browser context.

The attack requires user interaction—a victim must click on a malicious link—but no authentication is required from the attacker's perspective. Successful exploitation can result in high confidentiality impact through session token theft, with lower but still significant integrity and availability impacts.

Root Cause

The root cause stems from insufficient validation of URL parameters used in redirect operations within Grafana OSS. The application fails to properly sanitize and validate redirect destinations, allowing attackers to specify arbitrary paths including those that traverse the application's directory structure. This improper input validation enables the injection of malicious payloads that execute within the victim's browser session.

Attack Vector

The attack is network-based and requires minimal complexity to execute. An attacker crafts a malicious URL containing the open redirect payload combined with path traversal sequences. When a victim clicks this link, the Grafana application processes the request and redirects the user's browser in a way that exposes the XSS vulnerability.

The attack chain typically follows this pattern:

1. Attacker identifies a vulnerable redirect endpoint in Grafana
2. Attacker crafts a URL combining open redirect with path traversal to reach an XSS-vulnerable context
3. Victim receives the malicious link through phishing or other social engineering
4. Victim clicks the link while authenticated to Grafana
5. Malicious JavaScript executes in the victim's browser with access to their Grafana session

Due to the nature of this vulnerability, technical exploitation details are available in the Grafana Security Advisory. Organizations should review this advisory for complete technical information.

Detection Methods for CVE-2025-6023

Indicators of Compromise

• Unusual URL patterns in Grafana access logs containing path traversal sequences such as ../ or encoded variants
• HTTP requests to Grafana endpoints with suspicious redirect parameters pointing to external domains
• Browser-based alerts or anomalies reported by users accessing Grafana dashboards
• Unexpected authentication token usage patterns or session anomalies following link clicks

Detection Strategies

• Monitor web application firewall (WAF) logs for requests containing path traversal patterns targeting Grafana endpoints
• Implement content security policy (CSP) violation monitoring to detect unauthorized script execution attempts
• Deploy network intrusion detection signatures for open redirect exploitation patterns
• Review Grafana access logs for unusual redirect chains or suspicious referrer headers

Monitoring Recommendations

• Enable verbose logging on Grafana instances to capture full URL parameters in access logs
• Configure alerts for high volumes of redirect-related requests from single IP addresses
• Monitor for CSP violation reports indicating potential XSS exploitation attempts
• Implement user behavior analytics to detect session hijacking following potential XSS attacks

How to Mitigate CVE-2025-6023

Immediate Actions Required

• Upgrade Grafana OSS to a patched version immediately: 12.0.2+security-01, 11.6.3+security-01, 11.5.6+security-01, 11.4.6+security-01, or 11.3.8+security-01
• Audit access logs for signs of exploitation prior to patching
• Invalidate existing user sessions after applying the patch as a precautionary measure
• Notify users about the security update and advise against clicking untrusted Grafana links

Patch Information

Grafana has released security patches addressing this vulnerability across multiple version branches. Organizations should upgrade to the following fixed versions based on their current deployment:

For detailed patch information and download links, refer to the Grafana Security Release Blog Post.

Workarounds

• Deploy a Web Application Firewall (WAF) with rules to block requests containing path traversal patterns and suspicious redirect parameters
• Implement strict Content Security Policy headers to mitigate XSS impact if exploitation occurs before patching
• Restrict network access to Grafana instances using firewall rules to limit exposure to trusted IP ranges
• Consider placing Grafana behind an authentication proxy that validates all redirect destinations

# Example Nginx configuration to block path traversal attempts
location /grafana/ {
    # Block requests containing path traversal patterns
    if ($request_uri ~* "\.\.\/") {
        return 403;
    }
    
    # Add security headers
    add_header Content-Security-Policy "default-src 'self'; script-src 'self'" always;
    add_header X-Content-Type-Options "nosniff" always;
    add_header X-Frame-Options "SAMEORIGIN" always;
    
    proxy_pass http://grafana-backend:3000/;
}