CVE-2024-6727

Executive Summary

CVE-2024-6727 is a broken authentication vulnerability in Delphix Data Control Tower (DCT) versions prior to 19.0.0. The flaw exists within the enable-scale-testing functionality, allowing an unauthenticated attacker to bypass authentication mechanisms. With a CVSS score of 5.4 (Medium), this vulnerability could lead to unauthorized access to certain DCT features, potentially exposing sensitive configuration data or allowing limited manipulation of the environment. No public proof-of-concept (PoC) or exploit code has been identified at this time, and the EPSS score is 0.0%, indicating low exploitation activity in the wild. The vendor has addressed this issue in DCT version 19.0.0.

CVSS Breakdown & Threat Level

• CVSS Score: 5.4 (Medium)
• Attack Vector (AV): Network (N) – Exploitable remotely.
• Attack Complexity (AC): Low (L) – No special conditions required.
• Privileges Required (PR): None (N) – No authentication needed.
• User Interaction (UI): None (N) – No user action required.
• Scope (S): Unchanged (U) – Impact confined to the vulnerable component.
• Confidentiality (C): Low (L) – Limited information disclosure.
• Integrity (I): Low (L) – Limited data modification possible.
• Availability (A): None (N) – No impact on system availability.

Threat Level: Medium. The vulnerability is remotely exploitable without authentication, but the impact is limited to low confidentiality and integrity. The lack of public exploits and low EPSS score reduces immediate risk, but organizations using affected versions should prioritize patching.

Deep Dive & Mechanics

The vulnerability resides in the enable-scale-testing endpoint of Delphix DCT. This functionality is intended for internal testing and scaling operations but was exposed without proper authentication checks. The flaw allows an attacker to send crafted HTTP requests to this endpoint, bypassing the standard authentication gate.

Root Cause: The enable-scale-testing feature lacks a required authentication token or session validation. The application fails to verify the user's identity before processing requests to this endpoint, effectively treating all requests as authorized.

Attack Vector: An unauthenticated attacker can send a specially crafted HTTP request (e.g., POST or GET) to the vulnerable endpoint. The server processes the request without verifying the user's credentials, granting unauthorized access to the functionality.

Impact: Successful exploitation could allow an attacker to:

• Enable or disable scale-testing features.
• Potentially modify configuration parameters related to scaling.
• Access internal testing data or logs.
• Disrupt normal operations by altering scaling behavior.

The vulnerability does not provide full administrative access but could be used as a stepping stone for further attacks or to gather intelligence about the DCT environment.

Vulnerable vs. Patched Code

Vulnerable Code (Pre-19.0.0):

# Example of vulnerable endpoint handler
@app.route('/api/enable-scale-testing', methods=['POST'])
def enable_scale_testing():
    # Missing authentication check
    data = request.get_json()
    # Process request without verifying user identity
    scale_testing.enable(data)
    return jsonify({"status": "success"})

Patched Code (19.0.0+):

# Example of patched endpoint handler
@app.route('/api/enable-scale-testing', methods=['POST'])
@require_authentication  # Added authentication decorator
def enable_scale_testing():
    # Authentication is now enforced before processing
    data = request.get_json()
    scale_testing.enable(data)
    return jsonify({"status": "success"})

The patch introduces an authentication check (e.g., @require_authentication decorator) that validates the user's session token or API key before allowing access to the endpoint. This ensures only authenticated users can interact with the scale-testing functionality.

Exploitation & Lab Setup

Red Team

Lab Setup:

1. Deploy a vulnerable version of Delphix DCT (e.g., 18.x) in an isolated environment.
2. Identify the DCT server IP address (e.g., 192.168.1.100).
3. Use a tool like curl or Burp Suite to interact with the vulnerable endpoint.

Exploitation Steps:

1. Send a POST request to the vulnerable endpoint without any authentication headers:

   curl -X POST http://192.168.1.100/api/enable-scale-testing \
     -H "Content-Type: application/json" \
     -d '{"action": "enable", "parameters": {"test_mode": true}}'
   

2. Observe the response indicating success (e.g., {"status": "success"}).
3. Attempt to access other endpoints that may be exposed through this functionality.

Expected Outcome: The request is processed without authentication, granting unauthorized access to the scale-testing feature.

Blue Team

Detection:

• Monitor for requests to /api/enable-scale-testing without valid authentication tokens.
• Look for anomalous patterns in API logs, such as repeated requests from unknown IPs.
• Use the detection rules provided in the Detection Engineering section.

Mitigation:

• Immediately upgrade to DCT version 19.0.0 or later.
• If immediate patching is not possible, restrict network access to the DCT API using firewall rules or WAF policies.
• Implement additional monitoring for the vulnerable endpoint.

Indicators of Compromise (IOCs)

• Network IOCs:
  • HTTP requests to /api/enable-scale-testing without Authorization headers.
  • Unusual POST requests with JSON payloads containing "action": "enable" or "test_mode": true.
• Log IOCs:
  • API access logs showing 200 responses for /api/enable-scale-testing from unauthenticated sources.
  • Repeated failed authentication attempts followed by successful access to the endpoint.
• File IOCs:
  • Modified configuration files related to scale-testing (e.g., scale_testing.conf).

Detection Engineering

YARA Rule

rule CVE_2024_6727_Delphix_DCT_Broken_Auth {
    meta:
        description = "Detects exploitation attempts of CVE-2024-6727 in Delphix DCT"
        author = "Valters IT"
        date = "2024-01-01"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2024-6727"
    strings:
        $endpoint = "/api/enable-scale-testing"
        $action_enable = "enable"
        $test_mode = "test_mode"
    condition:
        $endpoint and ($action_enable or $test_mode)
}

Sigma Rule

title: CVE-2024-6727 Delphix DCT Broken Authentication
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects unauthenticated access to the enable-scale-testing endpoint in Delphix DCT
author: Valters IT
date: 2024-01-01
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2024-6727
logsource:
    category: webserver
    product: apache
    service: access
detection:
    selection:
        cs-uri-path: "/api/enable-scale-testing"
        cs-method: "POST"
        sc-status: 200
    filter:
        cs-auth: "*"  # Presence of authentication header
    condition: selection and not filter
falsepositives:
    - Legitimate authenticated requests to the endpoint
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2024-6727 Delphix DCT Broken Authentication Attempt"; flow:to_server; content:"POST"; http_method; content:"/api/enable-scale-testing"; http_uri; content:"enable"; http_client_body; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Upgrade: Update Delphix DCT to version 19.0.0 or later. This is the only complete fix.
2. Network Segmentation: Restrict access to the DCT API to trusted IP addresses using firewall rules.
3. WAF Rules: Deploy web application firewall (WAF) rules to block requests to /api/enable-scale-testing without proper authentication.

Long-Term Measures:

• Implement regular security audits of all API endpoints.
• Enforce authentication for all sensitive functionality.
• Monitor for similar vulnerabilities in future releases.

Workarounds (if patching is delayed):

• Disable the enable-scale-testing endpoint by modifying the application configuration (if possible).
• Use reverse proxy rules to block access to the vulnerable path.

Valters IT