CVE-2022-31123: Grafana Auth Bypass Vulnerability

CVE-2022-31123 Overview

CVE-2022-31123 is an authentication bypass vulnerability affecting Grafana, an open source observability and data visualization platform. The vulnerability allows attackers to bypass plugin signature verification, enabling the execution of malicious unsigned plugins even when unsigned plugins are explicitly disallowed by server configuration.

An attacker can convince a server administrator to download and run a malicious plugin that bypasses Grafana's signature verification mechanism. This represents a significant security risk as it undermines the trust model that organizations rely on to ensure only verified plugins are executed within their Grafana environments.

Critical Impact

Attackers can bypass plugin signature verification to execute malicious code on Grafana servers, potentially leading to full system compromise with high confidentiality, integrity, and availability impact.

Affected Products

• Grafana versions prior to 9.1.8
• Grafana versions prior to 8.5.14
• NetApp E-Series Performance Analyzer

Discovery Timeline

• 2022-10-13 - CVE-2022-31123 published to NVD
• 2024-11-21 - Last updated in NVD database

Technical Details for CVE-2022-31123

Vulnerability Analysis

This vulnerability is classified under CWE-347 (Improper Verification of Cryptographic Signature), indicating a fundamental flaw in how Grafana validates plugin authenticity. The signature verification bypass allows malicious actors to circumvent security controls designed to prevent unauthorized plugin execution.

The attack requires local access and user interaction, meaning an attacker must convince an administrator to download and install a crafted malicious plugin. Once installed, the plugin executes with the same privileges as the Grafana server process, potentially allowing complete system compromise.

The vulnerability affects the plugin installation workflow where signature validation should reject unsigned or improperly signed plugins. Due to the implementation flaw, malicious plugins can bypass these checks and execute arbitrary code on the target system.

Root Cause

The root cause lies in improper verification of cryptographic signatures during the plugin installation process. Grafana's plugin signature verification mechanism contains a logic flaw that allows specially crafted plugins to bypass signature validation checks, even when the server is configured to reject unsigned plugins.

Attack Vector

The attack requires local access and social engineering. An attacker must:

1. Create a malicious Grafana plugin designed to bypass signature verification
2. Convince a server administrator to download the malicious plugin
3. Have the administrator install the plugin through Grafana's plugin management interface

Once installed, the malicious plugin executes with Grafana server privileges, enabling data exfiltration, lateral movement, or persistent backdoor installation. The local attack vector combined with required user interaction means this is not directly exploitable remotely, but the high impact on confidentiality, integrity, and availability makes it a serious concern for organizations running vulnerable Grafana instances.

Detection Methods for CVE-2022-31123

Indicators of Compromise

• Presence of unsigned or unverified plugins in the Grafana plugins directory
• Plugin installation activity from unusual sources or untrusted repositories
• Unexpected network connections originating from the Grafana server process
• Anomalous file system activity in Grafana plugin directories

Detection Strategies

• Monitor Grafana plugin directory for newly installed or modified plugins
• Implement file integrity monitoring on Grafana installation directories
• Review Grafana server logs for plugin installation events from non-standard sources
• Audit administrative actions related to plugin management

Monitoring Recommendations

• Enable detailed logging for Grafana plugin operations and administrative actions
• Configure alerts for plugin installation events, especially from external sources
• Implement network monitoring to detect unusual outbound connections from Grafana servers
• Regularly audit installed plugins against known-good baseline configurations

How to Mitigate CVE-2022-31123

Immediate Actions Required

• Upgrade Grafana to version 9.1.8 or later (for 9.x branch) or version 8.5.14 or later (for 8.x branch)
• Audit currently installed plugins for any unsigned or suspicious entries
• Restrict administrative access to Grafana plugin management functionality
• Review and validate the source of all installed plugins

Patch Information

Grafana has released security patches addressing this vulnerability. Organizations should upgrade to the following fixed versions:

• Grafana 9.x branch: Upgrade to version 9.1.8 or later - GitHub Grafana Release v9.1.8
• Grafana 8.x branch: Upgrade to version 8.5.14 or later

For detailed patch information, refer to the GitHub Security Advisory GHSA-rhxj-gh46-jvw8. NetApp customers should also consult the NetApp Security Advisory ntap-20221124-0002.

Workarounds

• Do not install plugins downloaded from untrusted sources
• Implement strict network controls to prevent downloading plugins from unauthorized repositories
• Establish an organizational policy requiring plugin vetting before installation
• Limit administrative privileges to reduce the risk of social engineering attacks

# Verify Grafana version and check for vulnerable installations
grafana-cli --version

# List installed plugins for audit
grafana-cli plugins ls

# Update Grafana to patched version (example for Linux package managers)
# For Debian/Ubuntu:
sudo apt-get update && sudo apt-get install grafana

# For RHEL/CentOS:
sudo yum update grafana