CVE-2024-6796

Executive Summary

CVE-2024-6796 is a critical improper access control vulnerability in Baxter Connex health portal versions released before August 30, 2024. An unauthenticated attacker can exploit this flaw to gain unauthorized access to the Connex portal’s database and/or modify content. With a CVSS score of 8.2, the vulnerability poses a significant risk to healthcare data confidentiality and integrity. No public exploit code or proof-of-concept is currently available, and no patch has been released by Baxter. The EPSS score is 0.0%, indicating low exploitation activity in the wild, but the potential impact on patient data and healthcare operations is severe.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
• Base Score: 8.2 (High)
• Attack Vector: Network (AV:N)
• Attack Complexity: Low (AC:L)
• Privileges Required: None (PR:N)
• User Interaction: None (UI:N)
• Scope: Unchanged (S:U)
• Confidentiality Impact: High (C:H)
• Integrity Impact: High (I:H)
• Availability Impact: None (A:N)

Threat Level: High. The vulnerability allows unauthenticated remote attackers to read and modify sensitive healthcare data without any user interaction. The lack of a patch and the sensitive nature of the data make this a priority for defense.

Deep Dive & Mechanics

The vulnerability resides in the access control logic of the Baxter Connex health portal. The portal likely uses role-based access control (RBAC) to restrict database queries and content modifications to authenticated users. However, due to improper validation of user sessions or API endpoints, an unauthenticated attacker can bypass these controls.

Root Cause: The application fails to enforce authentication checks on certain API endpoints or database interfaces. This could be due to:

• Missing or misconfigured middleware that validates session tokens.
• Direct database access via exposed endpoints without authentication.
• Insecure direct object references (IDOR) that allow manipulation of database records.

Attack Vector: An attacker sends crafted HTTP requests to the Connex portal’s backend APIs. For example, a GET request to /api/patients might return all patient records without requiring a valid session token. Similarly, a POST request to /api/updateContent could modify portal content.

Impact: Unauthorized access to the database can lead to exposure of protected health information (PHI), patient records, and system configuration data. Content modification could be used to deface the portal, inject malicious scripts, or alter medical information, potentially endangering patient safety.

Vulnerable vs. Patched Code

Since no patch is available, we can only infer the vulnerable code pattern. The following examples illustrate the difference between vulnerable and secure access control implementations.

Vulnerable Code (Python Flask example):

from flask import Flask, request, jsonify
import sqlite3

app = Flask(__name__)

@app.route('/api/patients', methods=['GET'])
def get_patients():
    # No authentication check
    conn = sqlite3.connect('health.db')
    cursor = conn.cursor()
    cursor.execute("SELECT * FROM patients")
    patients = cursor.fetchall()
    return jsonify(patients)

Patched Code (Secure version):

from flask import Flask, request, jsonify, abort
import sqlite3
from functools import wraps

app = Flask(__name__)

def require_auth(f):
    @wraps(f)
    def decorated(*args, **kwargs):
        token = request.headers.get('Authorization')
        if not token or not validate_token(token):
            abort(401)
        return f(*args, **kwargs)
    return decorated

@app.route('/api/patients', methods=['GET'])
@require_auth
def get_patients():
    conn = sqlite3.connect('health.db')
    cursor = conn.cursor()
    cursor.execute("SELECT * FROM patients")
    patients = cursor.fetchall()
    return jsonify(patients)

The patched version adds a require_auth decorator that validates the session token before allowing access to the endpoint.

Exploitation & Lab Setup

Red Team

Lab Environment:

• Target: Baxter Connex portal (version prior to 8/30/2024)
• Attacker: Kali Linux with Burp Suite and curl

Exploitation Steps:

1. Reconnaissance: Identify exposed API endpoints using directory brute-forcing or by analyzing the portal’s JavaScript files.

   gobuster dir -u http://target-connex.com -w /usr/share/wordlists/dirb/common.txt -x php,asp,aspx
   

2. Test for Unauthenticated Access: Send a direct request to a sensitive endpoint without any authentication headers.

   curl -v http://target-connex.com/api/patients
   

3. Database Access: If the endpoint returns data, attempt to extract all records.

   curl -X GET http://target-connex.com/api/patients?limit=1000
   

4. Content Modification: Try to modify portal content via POST requests.

   curl -X POST http://target-connex.com/api/updateContent -H "Content-Type: application/json" -d '{"page":"home","content":"<script>alert(1)</script>"}'
   

Expected Outcome: Unauthenticated access to patient data and ability to modify portal content.

Blue Team

Detection & Response:

1. Monitor for Unauthenticated API Access: Look for requests to sensitive endpoints (e.g., /api/patients, /api/updateContent) that lack Authorization headers.
2. Anomalous Data Exfiltration: Detect large volumes of data being retrieved from the portal, especially from IPs not associated with legitimate users.
3. Content Integrity Checks: Implement file integrity monitoring (FIM) on portal content files to detect unauthorized modifications.

Honeypot Strategy: Deploy a fake API endpoint that mimics the vulnerable behavior and logs all access attempts for threat intelligence.

Indicators of Compromise (IOCs)

• Network IOCs:

  • Unusual HTTP requests to /api/patients, /api/updateContent, or similar endpoints without authentication.
  • High volume of GET requests from a single IP to database-related endpoints.
  • POST requests to content modification endpoints with suspicious payloads (e.g., JavaScript, SQL).

• File IOCs:

  • Unexpected changes to portal HTML files or database entries.
  • New files in web root directories (e.g., shell.php, backdoor.asp).

• Log IOCs:

  • Web server logs showing 200 responses to unauthenticated API calls.
  • Database logs showing queries from unknown IPs.

Detection Engineering

YARA Rule

rule CVE_2024_6796_Unauthenticated_Access {
    meta:
        description = "Detects unauthenticated access attempts to Baxter Connex portal API endpoints"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2024-6796"
    strings:
        $api_patients = "/api/patients"
        $api_update = "/api/updateContent"
        $no_auth = "Authorization:"
    condition:
        any of ($api*) and not $no_auth
}

Sigma Rule

title: Unauthenticated Access to Baxter Connex Portal API
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects HTTP requests to sensitive Connex API endpoints without authentication headers
author: Valters IT
date: 2025/04/10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-uri-stem:
            - '/api/patients'
            - '/api/updateContent'
            - '/api/database'
        cs-headers: 'Authorization:'
    condition: selection and not cs-headers
falsepositives:
    - Legitimate unauthenticated endpoints (if any)
level: high

Suricata Rule

alert http $EXTERNAL_NET any -> $HOME_NET any (
    msg:"CVE-2024-6796 - Unauthenticated Access to Baxter Connex Portal API";
    flow:to_server,established;
    content:"/api/patients"; http_uri;
    content:!"Authorization"; http_header;
    classtype:attempted-recon;
    sid:1000001;
    rev:1;
)

Remediation & Mitigation

Immediate Actions:

1. Isolate the Connex portal from the internet if possible, or restrict access via VPN/firewall rules to trusted IPs.
2. Implement a Web Application Firewall (WAF) to block requests to sensitive API endpoints without authentication headers.
3. Monitor logs for any signs of exploitation and rotate any exposed credentials.

Long-Term Fix:

• Apply the vendor’s update once released (after August 30, 2024).
• Conduct a thorough code review of all API endpoints to ensure proper authentication and authorization checks.
• Implement network segmentation to limit the blast radius of a compromise.

Workaround:

• If patching is not possible, disable the vulnerable API endpoints or add authentication middleware at the reverse proxy level (e.g., Nginx, Apache).

Valters IT
Securing Healthcare, One Vulnerability at a Time