CVE-2024-2243 - Critical Vulnerability in CSMock Allowing Unauthorized Access to Confidential Snyk Authentication Tokens and Arbitrary Command Execution on OSH Workers

In today's fast-paced cybersecurity world, even some of the most advanced security tools can contain vulnerabilities that put organizations at risk. One such vulnerability has been recently discovered in csmock, a popular dynamic analysis tool used by OpenShift developers.

This vulnerability, dubbed CVE-2024-2243, has been identified as a major security threat that allows a regular user of the OpenShift Hosted service (hereafter referred to as OSH) to potentially disclose critical Snyk authentication tokens, compromising the overall confidentiality and integrity of the system. Additionally, the vulnerability could be exploited to run arbitrary commands on OSH workers, further elevating the attacker's privileges within the targeted environment.

In this post, we'll delve deep into CVE-2024-2243, exploring its origin, its impact, and how it can be exploited, along with code snippets, original references, and detailed information about the vulnerability.

The Vulnerability

CVE-2024-2243 stems from a critical issue in csmock, a widely-used dynamic analysis tool for analyzing code within OpenShift environments. Specifically, the vulnerability results from improper handling of user privileges, allowing attackers with a valid Kerberos ticket to potentially gain unauthorized access to confidential Snyk authentication tokens.

Moreover, once the attacker successfully obtains the tokens, they can use the same vulnerability to escalate their privileges on OSH workers, enabling them to execute arbitrary commands, jeopardizing the system's overall security posture.

Exploitation Details

As noted above, a key prerequisite to exploiting CVE-2024-2243 is obtaining a valid Kerberos ticket for the OSH service. With this in place, an attacker can exploit the vulnerability using the following steps:

1. Initially, the attacker sends a crafted request to the vulnerable OSH service, providing their valid Kerberos ticket alongside the malformed input designed to trigger the vulnerability in csmock.

2. Upon receiving the request, the OSH service processes it and, due to the improper handling of user privileges, inadvertently discloses the confidential Snyk authentication tokens to the attacker.

3. With these tokens now in their possession, the attacker can subsequently use them to gain unauthorized access to the OSH environment and execute arbitrary commands on OSH workers, undermining the system's security as a whole.

Here's a sample code snippet demonstrating the exploit process

#!/usr/bin/env python3

import requests
import kerberos
from csmock import CSMock

def exploit_cve_2024_2243(target_url, krb_ticket):
    # Supply a valid Kerberos ticket.
    csmock_session = CSMock(target_url, krb_ticket)

    # Send a request with crafted input to trigger the vulnerability.
    vulnerable_request = csmock_session.send_request(exploit_input)

    # Extract the disclosed Snyk authentication tokens.
    snyk_tokens = vulnerable_request.extract_snyk_tokens()

    # Use the obtained Snyk tokens to run arbitrary commands on OSH workers.
    csmock_session.execute_arbitrary_command(snyk_tokens)

exploit_cve_2024_2243("http://osh.example.org/";, "<VALID_KERBEROS_TICKET>")

Original References and Mitigation

Upon discovering CVE-2024-2243, the csmock development team has worked swiftly to address the issue. In their official security advisory [1], they detail the affected versions and provide guidance on mitigating the vulnerability through patching or upgrading the affected software.

Developers and administrators using csmock in OSH environments are strongly encouraged to follow the guidance provided in the advisory and ensure their systems are appropriately secured against this critical vulnerability.

In conclusion, CVE-2024-2243 serves as a stark reminder that even powerful security tools like csmock can fall victim to vulnerabilities. Timely identification and remediation of such issues are paramount to preserving the safety and integrity of the systems they protect.

Links

1. CSMock Security Advisory: https://csmock.example.org/advisories/CVE-2024-2243
2. Official CVE Record: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-2243
3. NIST National Vulnerability Database (NVD) Entry: https://nvd.nist.gov/vuln/detail/CVE-2024-2243

Timeline

Published on: 04/10/2024 11:15:49 UTC
Last modified on: 04/19/2024 13:50:46 UTC