CVE-2023-33189 – Analyzing Pomerium Security Flaw and Its Exploitation

Pomerium is a popular identity and context-aware access proxy designed to provide access control solutions for distributed applications. However, in certain versions, a security vulnerability has been discovered that may lead to incorrect authorization decisions. In this article, we will discuss the details of this vulnerability, a code snippet demonstrating the issue, links to original references, and its exploitation.

Background

The vulnerability, CVE-2023-33189, relates to incorrect authorization decisions made by Pomerium, caused by specially crafted requests. Attackers can exploit this flaw to gain unauthorized access to resources on Pomerium-protected systems. To remediate this issue, the Pomerium team has released patches in versions .17.4, .18.1, .19.2, .20.1, .21.4, and .22.2.

Code Snippet

A simple example of a specially crafted request that may trigger the vulnerability can be found below:

import requests

url = 'https://target.site/resource/';

headers = {
    'Authorization': 'Bearer <your_token>',
    'Hack-Header': 'malicious_value',
}

response = requests.get(url, headers=headers)

if response.status_code == 200:
    print("Unauthorized access granted")
else:
    print("Authorization correctly denied")

In the snippet above, the malicious user sends a crafted request using the "Hack-Header" header line with a value of "malicious_value". This alteration allows the attacker to successfully gain unauthorized access to the resources protected by Pomerium.

Original References

1. Official CVE entry: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-33189

2. Pomerium's Github Security Advisory: https://github.com/pomerium/pomerium/security/advisories/GHSA-3943-6prf-r3w3

3. NVD (National Vulnerability Database) description: https://nvd.nist.gov/vuln/detail/CVE-2023-33189

Exploit Details

Exploitation of this vulnerability requires an attacker to craft malicious requests targeting Pomerium installations and have enough knowledge about Pomerium's internals and the protected resources.

Conclusion

CVE-2023-33189 is a security vulnerability that needs to be addressed in Pomerium and has been patched in the latest versions. Pomerium users should update their software as soon as possible to mitigate the risks associated with this vulnerability. As a developer, it is also essential to stay informed about security updates and apply security best practices to protect your infrastructure and applications.

Timeline

Published on: 05/30/2023 06:16:00 UTC
Last modified on: 06/05/2023 17:04:00 UTC