CVE-2022-23536 Explained : Impact and Mitigation

This article discusses a vulnerability in Alertmanager that can expose local file content via a specially crafted configuration in Cortex versions 1.13.0, 1.13.1, and 1.14.0.

Understanding CVE-2022-23536

This CVE highlights a local file inclusion vulnerability within Cortex's Alertmanager that could allow a threat actor to read local files remotely through maliciously crafted configurations.

What is CVE-2022-23536?

Cortex, a tool providing multi-tenant, long-term storage for Prometheus, is impacted by a security vulnerability in its Alertmanager component. The issue arises when processing specific configurations submitted to the Alertmanager Set Configuration API.

The Impact of CVE-2022-23536

The vulnerability in Cortex's Alertmanager in versions 1.13.0, 1.13.1, and 1.14.0 poses a significant risk to data confidentiality, allowing unauthorized access to sensitive local files through specially designed configurations.

Technical Details of CVE-2022-23536

This section delves into the specifics of the vulnerability within Alertmanager in Cortex, detailing its description, affected systems, and the exploitation mechanism.

Vulnerability Description

A local file inclusion vulnerability in Cortex versions 1.13.0, 1.13.1, and 1.14.0 enables threat actors to read local files by sending malicious Alertmanager configurations via the Set Configuration API.

Affected Systems and Versions

Cortex versions 1.13.0, 1.13.1, and 1.14.0 are vulnerable to this exploit, affecting users who have

-experimental.alertmanager.enable-api

or

enable_api: true

configured.

Exploitation Mechanism

Malicious actors exploit this vulnerability by submitting specially crafted configurations to the Alertmanager Set Configuration API, which allows remote reading of local files.

Mitigation and Prevention

In this section, we cover the immediate steps to take to address the CVE, suggest long-term security practices, and emphasize the importance of patching and updates.

Immediate Steps to Take

Users of Cortex Alertmanager are advised to upgrade to the patched versions, 1.13.2 or 1.14.1, to mitigate the vulnerability. Alternatively, administrators can reject configurations with the

api_key_file

setting in the

opsgenie_configs

section.

Long-Term Security Practices

To enhance security posture, best practices involve regular security audits, implementing strict input validation, and staying informed about security advisories relevant to the software stack.

Patching and Updates

Regularly applying security patches and updates are essential to safeguard against emerging threats. Promptly applying the patches released by Cortex for versions 1.13.2 and 1.14.1 is crucial to addressing CVE-2022-23536.