CVE-2022-39328: Grafana Race Condition Vulnerability

CVE-2022-39328 Overview

CVE-2022-39328 is a race condition vulnerability in Grafana, an open-source monitoring and observability platform. The flaw resides in the authentication middleware logic and affects versions starting with 9.2.0 and earlier than 9.2.4. Under heavy load, the race condition allows an unauthenticated user to query an administration endpoint. The issue is patched in version 9.2.4, and no workarounds exist. The vulnerability is tracked under [CWE-362] (Concurrent Execution using Shared Resource with Improper Synchronization).

Critical Impact
Unauthenticated attackers can reach Grafana administration endpoints under high concurrency, leading to compromise of confidentiality, integrity, and availability.

Affected Products

Grafana versions 9.2.0 through 9.2.3
Grafana OSS and Enterprise builds derived from the affected branch
Downstream products bundling vulnerable Grafana versions (see NetApp advisory)

Discovery Timeline

2022-11-08 - CVE-2022-39328 published to the National Vulnerability Database (NVD)
2024-11-21 - Last updated in NVD database

Technical Details for CVE-2022-39328

Vulnerability Analysis

The vulnerability is a race condition in Grafana's authentication middleware. When the server processes concurrent HTTP requests under heavy load, the middleware fails to consistently enforce authentication checks before routing requests to protected handlers. An attacker who issues many parallel requests to administrative endpoints can win the race and reach functionality intended only for authenticated administrators.

The issue affects network-reachable Grafana instances and requires no privileges or user interaction. Exploitation complexity is high because the attacker must produce sustained, concurrent traffic to reliably trigger the race window. Successful exploitation grants access to administration endpoints that expose sensitive configuration, user management, and data source controls.

Root Cause

The defect stems from improper synchronization between the authentication middleware and downstream request handlers. Shared state used to determine whether a request is authenticated is read and written without sufficient locking or atomicity guarantees. The window between the check and the use of that state allows requests in flight to bypass the authentication decision. The fix in 9.2.4 corrects the synchronization logic so that authentication state is evaluated reliably on every request.

Attack Vector

The attack vector is network based. An unauthenticated attacker sends a large volume of concurrent requests to a Grafana administration endpoint over HTTP or HTTPS. When server load is high enough to expose the race window, some requests bypass authentication and execute against admin functionality. No verified public proof-of-concept exploit is currently listed in the enriched data, and the CVE is not on the CISA Known Exploited Vulnerabilities catalog. Refer to the Grafana GitHub Security Advisory for vendor technical detail.

Detection Methods for CVE-2022-39328

Indicators of Compromise

Bursts of concurrent HTTP requests to Grafana administrative paths such as /api/admin/* from a single source IP or a small cluster of sources.
Successful HTTP 200 responses to administrative endpoints without preceding authenticated session cookies or valid Authorization headers.
Unexpected administrative changes (new users, modified data sources, altered organizational settings) outside scheduled administration windows.

Detection Strategies

Inspect Grafana access logs for high-rate parallel requests targeting /api/admin/, /api/users/, or /api/orgs/ endpoints.
Correlate web server, reverse proxy, and Grafana application logs to identify admin endpoint responses lacking authentication context.
Alert on Grafana audit log entries showing privileged actions with empty or anonymous user identifiers.

Monitoring Recommendations

Forward Grafana application and audit logs to a centralized analytics platform for retention and query.
Baseline normal administrative request volume and rate, then alert on statistical deviations.
Monitor for sudden spikes in 4xx/5xx ratios on admin endpoints, which can indicate brute-force concurrency attempts against the race window.

How to Mitigate CVE-2022-39328

Immediate Actions Required

Upgrade all Grafana instances running 9.2.0 through 9.2.3 to version 9.2.4 or later.
Audit administrative users, API keys, service accounts, and data sources for unauthorized changes since the deployment of any affected version.
Restrict network access to Grafana administration endpoints using firewall rules, reverse proxies, or VPN-only exposure.

Patch Information

Grafana addresses this vulnerability in release 9.2.4. The patch corrects the synchronization defect in the authentication middleware. Operators running Grafana through distribution channels such as NetApp products should consult the NetApp Security Advisory NTAP-20221215-0003 for downstream fix timelines. The vendor advisory is published at the Grafana GitHub Security Advisory GHSA-vqc4-mpj8-jxch.

Workarounds

No vendor-supplied workarounds exist; upgrading to 9.2.4 is the only complete fix.
As a compensating control, place Grafana behind an authenticating reverse proxy that enforces identity before requests reach the Grafana process.
Apply rate limiting on administrative paths at the reverse proxy or WAF to reduce the probability of triggering the race window.

bash

# Example: NGINX rate limiting and access restriction for Grafana admin endpoints
limit_req_zone $binary_remote_addr zone=grafana_admin:10m rate=5r/s;

server {
    listen 443 ssl;
    server_name grafana.example.com;

    location /api/admin/ {
        allow 10.0.0.0/8;
        deny all;
        limit_req zone=grafana_admin burst=10 nodelay;
        proxy_pass http://grafana_backend;
    }

    location / {
        proxy_pass http://grafana_backend;
    }
}