External risk intelligence

Grafana Snapshot Data Viewing and Deletion Vulnerability

CVE advisoryKnown Exploit

CVE-2021-39226

A vulnerability in Grafana allows unauthorized users to view and delete snapshot data. This could lead to complete data loss and disrupt business operations. Affected organizations should apply vendor-provided updates to mitigate this risk.

4Halo Surface Signal

Authentication Bypass

Grafana

before 7.5.118.0.0 to before 8.1.63435

External exposure likelihood

Halo Surface Signal score for CVE-2021-39226

Grafana is commonly deployed as a web-based data visualization platform. In many real-world environments, these interfaces are intended to be accessible to users over the network, often serving as central dashboards that may be exposed to internal or external users, making web-based endpoints frequently reachable.

Horizon Alert

Summary of the vulnerability and why it matters

The Grafana data visualization platform contains a flaw that permits unauthorized access and modification of snapshot data. This vulnerability allows for both viewing and deleting snapshots, which can lead to the complete loss of snapshot information. The core issue involves improper access controls related to snapshot functionality within the platform.

  • Grafana snapshot feature
  • Unauthorized viewing and deletion of data
  • Complete snapshot data loss

Attack Path

How an attacker could exploit the issue

The vulnerability allows attackers to gain unauthorized access to sensitive snapshot data within the Grafana platform. This exposure can lead to the viewing and deletion of all snapshot information, resulting in significant data loss for affected organizations. The attack leverages specific literal paths to interact with snapshot data, bypassing normal access controls.

  • Exposure: Network accessible snapshots.
  • Attacker access: Direct path to snapshot data.
  • Trigger: View or delete snapshot data.

Live Threat

Current exploitation, exposure, and threat context

The vulnerability allows unauthorized access to sensitive data within the Grafana platform, potentially leading to data loss. This could impact organizations by exposing internal information and disrupting operations through data deletion. The ease of exploitation and potential for significant damage necessitate prompt attention.

  • Attacker skill level: Low
  • Required access or conditions: Network access
  • Business risk or urgency: High

Priority actions

Operational Fix

Recommended remediation, mitigation, and detection steps

This vulnerability allows unauthorized users to access and delete snapshot data within Grafana, potentially leading to complete data loss. An organization can mitigate this risk by identifying affected systems, implementing protective measures, applying the vendor's fix, and verifying the solution. Continuous monitoring is advised to detect any related malicious activity.

  • Find Grafana instances.
  • Block snapshot API paths.
  • Update Grafana to the latest version.
  • Verify the fix implementation.
  • Monitor for related activity.

Frequently asked questions

What is the Grafana vulnerability that allows unauthorized viewing and deletion of snapshot data?

CVE-2021-39226 is a vulnerability in Grafana that permits unauthenticated and authenticated users to view and delete snapshot data. This can result in the complete loss of all snapshot information. The issue arises from improper access controls related to Grafana's snapshot functionality.

What type of weakness does CVE-2021-39226 exhibit, and how does it affect Grafana?

This vulnerability exhibits weaknesses classified as CWE-287 (Improper Authentication) and CWE-862 (Type Safety). It allows unauthenticated users to view snapshots and, if 'public_mode' is enabled, to delete them. Authenticated users can also delete snapshots regardless of the 'public_mode' setting.

How can an attacker exploit the Grafana snapshot vulnerability, and what is the scope of impact?

An attacker can exploit this by accessing specific literal paths like /dashboard/snapshot/:key or /api/snapshots/:key to view the snapshot with the lowest database key. Deletion can occur via /api/snapshots/:key or /api/snapshots-delete/:deleteKey. The scope is the complete loss of all snapshot data, enabling a full walkthrough of snapshot contents.

How relevant is the Grafana snapshot vulnerability, and is it actively exploited?

The Grafana snapshot vulnerability (CVE-2021-39226) is listed on the Known Exploited Vulnerabilities (KEV) catalog, indicating active exploitation. The CISA has identified it as a significant threat, necessitating prompt action. Its network accessibility and potential for data loss make it highly relevant.

What are the recommended steps to mitigate the Grafana snapshot data vulnerability?

To mitigate this vulnerability, organizations should first identify all Grafana instances. A practical interim measure is to use a reverse proxy to block access to the literal paths: /api/snapshots/:key, /api/snapshots-delete/:key, /dashboard/snapshot/:key, and /api/snapshots/:key, as these have no normal function. The primary fix is to update Grafana to versions 8.1.6 or 7.5.11. Continuous monitoring for related malicious activity is also advised.

References