CVE-2022-23498: Grafana Session Hijacking Vulnerability

CVE-2022-23498 Overview

CVE-2022-23498 is a session hijacking vulnerability in Grafana, the popular open-source platform for monitoring and observability. When datasource query caching is enabled, Grafana caches all headers including the grafana_session cookie. This improper handling of sensitive session data allows any authenticated user who queries a datasource with caching enabled to potentially acquire another user's session, leading to unauthorized access and account takeover.

Critical Impact

Authenticated attackers can hijack other users' sessions by exploiting the datasource query caching mechanism, potentially gaining access to sensitive monitoring data, dashboards, and administrative functions depending on the hijacked user's privileges.

Affected Products

• Grafana versions 8.3.0-beta1 through 9.2.9
• Grafana versions 9.3.0 through 9.3.3
• Grafana Grafana

Discovery Timeline

• 2023-02-03 - CVE CVE-2022-23498 published to NVD
• 2024-11-21 - Last updated in NVD database

Technical Details for CVE-2022-23498

Vulnerability Analysis

This vulnerability stems from an insecure caching implementation in Grafana's datasource query caching feature. When caching is enabled for a datasource, Grafana incorrectly includes all HTTP headers in the cached response, including the sensitive grafana_session cookie. This design flaw creates a session hijacking condition where subsequent users querying the same datasource can retrieve cached session tokens belonging to other users.

The vulnerability is classified under CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor), as the system inadvertently exposes authentication credentials through the caching mechanism. An attacker with low privileges (any authenticated user) can exploit this vulnerability over the network without any user interaction required.

Root Cause

The root cause lies in Grafana's datasource query caching implementation, which fails to properly filter sensitive authentication headers before storing cached responses. The caching mechanism was designed to improve query performance but did not account for the security implications of caching session-related data. Specifically, the grafana_session cookie is treated as a regular header and included in cached responses, rather than being excluded as sensitive authentication material.

Attack Vector

The attack vector requires network access to a Grafana instance where datasource query caching is enabled. An authenticated attacker executes a query against a cached datasource. If another user has previously queried the same datasource, their session token may be present in the cached response. The attacker can then extract this session token and use it to impersonate the victim user, gaining access to their dashboards, data sources, and any administrative functions they may have access to.

The attack is particularly concerning in multi-tenant or shared Grafana environments where users with different privilege levels access the same datasources. A low-privileged user could potentially hijack an administrator's session, leading to complete compromise of the Grafana instance.

Detection Methods for CVE-2022-23498

Indicators of Compromise

• Unusual session activity where a single session token appears to be used from multiple IP addresses or geographic locations
• Audit logs showing user actions inconsistent with normal behavior patterns for that account
• Multiple concurrent sessions for the same user from different endpoints
• Unexpected datasource queries from users who don't typically access those resources

Detection Strategies

• Monitor Grafana authentication logs for session anomalies and concurrent access patterns
• Implement network-level monitoring to detect session token reuse across different client IP addresses
• Review datasource caching configurations to identify potentially vulnerable deployments
• Analyze Grafana audit logs for privilege escalation or unauthorized data access attempts

Monitoring Recommendations

• Enable comprehensive audit logging in Grafana to track all authentication and authorization events
• Implement alerting for session anomalies such as geographic impossibility or rapid IP changes
• Monitor for bulk data access or unusual query patterns that might indicate session compromise
• Establish baseline user behavior profiles to detect deviations indicative of account takeover

How to Mitigate CVE-2022-23498

Immediate Actions Required

• Upgrade Grafana to version 9.2.10 or 9.3.4 or later immediately
• If immediate upgrade is not possible, disable datasource query caching for all datasources as a temporary mitigation
• Invalidate all active sessions and force re-authentication for all users
• Review audit logs for signs of session hijacking or unauthorized access

Patch Information

Grafana has released security patches addressing this vulnerability. Organizations should upgrade to Grafana version 9.2.10 or 9.3.4 or later. The patches properly exclude sensitive authentication headers from the datasource query cache, preventing session token leakage.

For detailed patch information, refer to the Grafana Security Advisory GHSA-2j8f-6whh-frc8.

Workarounds

• Disable datasource query caching for all datasources until the patch can be applied
• Implement network segmentation to limit which users can access sensitive datasources
• Consider implementing additional session validation controls such as IP binding or shorter session timeouts
• Monitor for suspicious activity and be prepared to invalidate sessions if compromise is suspected

# Configuration example - Disable datasource query caching in Grafana
# In grafana.ini configuration file:
[caching]
# Disable caching to mitigate CVE-2022-23498
enabled = false

# Alternatively, disable caching per-datasource through the Grafana UI
# Navigate to Configuration > Data Sources > [Your Datasource] > Query Caching
# Set "Enable caching" to OFF