CVE-2022-46146: Security Vulnerability in Prometheus Exporter Toolkit - Authentication Cache Poisoning

Prometheus Exporter Toolkit is a widely used utility package designed to help in building exporters for various system metrics. Recently, a security vulnerability (CVE-2022-46146) was reported in the toolkit that affects versions prior to .7.2 and .8.2. This vulnerability allows an attacker with access to a Prometheus web.yml file and users' bcrypted passwords to bypass security measures by poisoning the built-in authentication cache. The developers of the toolkit have released a fix for the issue in versions .7.2 and .8.2.

Vulnerability Details

This security vulnerability revolves around the authentication cache mechanism in the Prometheus Exporter Toolkit. If an attacker gains access to the hashed (bcrypted) passwords of users and the web.yml file, they can poison the authentication cache such that they can bypass the security protocols. Essentially, this provides the attacker with unauthorized access and control over the system.

To fully comprehend this issue, let's consider the following code snippet that demonstrates a simple use case of the Prometheus Exporter Toolkit:

#!/usr/bin/env python3
import sys
from prometheus_client import start_http_server, Gauge

def collect_metrics():
    g = Gauge('my_metric', 'A sample metric')
    g.set(len(sys.argv))

if __name__ == '__main__':
    start_http_server(800)
    collect_metrics()

In this example, the exporter starts an HTTP server to expose the metric my_metric. The attacker can bypass the security mechanism if they gain unauthorized access to this system using poisoned authentication cache.

Solution

The developers of the Prometheus Exporter Toolkit released a fix for this issue in versions .7.2 and .8.2. Therefore, it is highly recommended to update your Prometheus Exporter Toolkit to one of these versions to avoid any security breaches due to this vulnerability.

Here are the links to the original references regarding this security issue

- GitHub Patch for .7.2
- GitHub Patch for .8.2

Please note that there is no workaround for this issue. For an attacker to exploit this vulnerability, they must have access to the hashed password and the Prometheus web.yml file. As such, it is crucial to maintain best security practices, ensuring the confidentiality and integrity of password files.

Conclusion

CVE-2022-46146 is a critical security vulnerability in the Prometheus Exporter Toolkit affecting versions prior to .7.2 and .8.2. By poisoning the built-in authentication cache, attackers with access to users' hashed passwords and the web.yml file can bypass the security protocols. It is imperative to update your Prometheus Exporter Toolkit to the latest patched version (.7.2 or .8.2) and secure your systems against potential unauthorized access.

Timeline

Published on: 11/29/2022 14:15:00 UTC
Last modified on: 02/01/2023 15:39:00 UTC