CVE-2021-28148
📋 TL;DR
This vulnerability allows unauthenticated attackers to send unlimited requests to a specific Grafana Enterprise API endpoint, causing denial of service (DoS) by overwhelming the server. It affects Grafana Enterprise instances with vulnerable versions that have the usage insights feature enabled.
💻 Affected Systems
- Grafana Enterprise
📦 What is this software?
Grafana by Grafana
Grafana by Grafana
Grafana by Grafana
⚠️ Risk & Real-World Impact
Worst Case
Complete service unavailability for all Grafana Enterprise users due to resource exhaustion from unlimited unauthenticated requests.
Likely Case
Service degradation or temporary outages from DoS attacks, disrupting monitoring and dashboard access.
If Mitigated
Minimal impact if proper network segmentation and rate limiting are in place, though authentication bypass remains.
🎯 Exploit Status
Exploitation requires only HTTP requests to the vulnerable endpoint without authentication. Simple tools like curl or scripts can be used.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 6.7.6, 7.3.10, or 7.4.5
Vendor Advisory: https://community.grafana.com/t/grafana-enterprise-6-7-6-7-3-10-and-7-4-5-security-update/44724
Restart Required: Yes
Instructions:
1. Backup your Grafana configuration and database. 2. Download the patched version from Grafana's official site. 3. Stop the Grafana service. 4. Install the update following Grafana's upgrade guide. 5. Restart the Grafana service. 6. Verify the version and functionality.
🔧 Temporary Workarounds
Disable Usage Insights API
allTemporarily disable the vulnerable usage insights HTTP API endpoint if not required.
Modify grafana.ini: [usage_insights] enabled = false
Restart Grafana service
Network Access Control
linuxRestrict access to Grafana Enterprise instance using firewall rules or network segmentation.
iptables -A INPUT -p tcp --dport 3000 -s trusted_networks -j ACCEPT
iptables -A INPUT -p tcp --dport 3000 -j DROP
🧯 If You Can't Patch
- Implement strict network segmentation to limit Grafana access to trusted IPs only
- Deploy web application firewall (WAF) with rate limiting and anomaly detection
🔍 How to Verify
Check if Vulnerable:
Check Grafana version via web interface or API: curl -s http://grafana-host:3000/api/health | grep versionCheck Version:
grafana-cli --version or check /etc/grafana/grafana.iniVerify Fix Applied:
Confirm version is 6.7.6, 7.3.10, 7.4.5 or later. Test API endpoint requires authentication.📡 Detection & Monitoring
Log Indicators:
- High volume of requests to /api/usage-insights endpoints from unauthenticated sources
- Increased error rates or timeout logs
Network Indicators:
- Spike in traffic to Grafana port 3000 from diverse IPs
- Unusual request patterns to specific API paths
SIEM Query:
source="grafana.log" AND ("usage-insights" OR "api/usage") AND status=200 AND user="anonymous" | stats count by src_ip🔗 References
- https://community.grafana.com/t/grafana-enterprise-6-7-6-7-3-10-and-7-4-5-security-update/44724
- https://community.grafana.com/t/release-notes-v6-7-x/27119
- https://grafana.com/blog/2021/03/18/grafana-6.7.6-7.3.10-and-7.4.5-released-with-important-security-fixes-for-grafana-enterprise/
- https://grafana.com/docs/grafana/latest/release-notes/release-notes-7-3-10/
- https://grafana.com/docs/grafana/latest/release-notes/release-notes-7-4-5/
- https://grafana.com/products/enterprise/
- https://security.netapp.com/advisory/ntap-20210430-0005/
- https://www.openwall.com/lists/oss-security/2021/03/19/5
- https://community.grafana.com/t/grafana-enterprise-6-7-6-7-3-10-and-7-4-5-security-update/44724
- https://community.grafana.com/t/release-notes-v6-7-x/27119
- https://grafana.com/blog/2021/03/18/grafana-6.7.6-7.3.10-and-7.4.5-released-with-important-security-fixes-for-grafana-enterprise/
- https://grafana.com/docs/grafana/latest/release-notes/release-notes-7-3-10/
- https://grafana.com/docs/grafana/latest/release-notes/release-notes-7-4-5/
- https://grafana.com/products/enterprise/
- https://security.netapp.com/advisory/ntap-20210430-0005/
- https://www.openwall.com/lists/oss-security/2021/03/19/5
