CVE-2024-50693

Executive Summary

CVE-2024-50693 identifies an Insecure Direct Object Reference (IDOR) vulnerability in SunGrow iSolarCloud, a cloud-based solar energy management platform. The flaw resides in the userService API model, allowing an authenticated attacker to manipulate object references (e.g., user IDs, device IDs) to access or modify data belonging to other users without proper authorization. This can lead to unauthorized disclosure of sensitive user information, device configurations, and potential manipulation of solar energy systems. The vendor released a remediation on October 31, 2024, but no specific patched version has been publicly disclosed. No public proof-of-concept (PoC) or exploit code is available at this time.

Supply Chain & Package Security

This vulnerability is not related to NPM, PyPI, Go, or Ruby packages. It affects a proprietary cloud application (iSolarCloud) and its backend API. Supply chain risk is limited to the vendor’s internal development and deployment pipeline.

CVSS Breakdown & Threat Level

CVSS Score: 0.0 (No vector provided by NVD)
Given the nature of IDOR in a cloud API, a reasonable CVSSv3.1 vector would be:
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N

• Attack Vector (AV): Network – exploitable remotely.
• Attack Complexity (AC): Low – no special conditions.
• Privileges Required (PR): Low – requires a valid user account.
• User Interaction (UI): None – no victim action needed.
• Scope (S): Unchanged – attacker cannot affect other resources.
• Confidentiality (C): High – sensitive user/device data exposed.
• Integrity (I): Low – limited ability to modify data.
• Availability (A): None – no denial of service.

Threat Level: High (due to potential data breach and impact on critical energy infrastructure).

Deep Dive & Mechanics

The vulnerability is an Insecure Direct Object Reference (CWE-639) in the userService API model of SunGrow iSolarCloud. The API likely exposes endpoints that accept user-supplied identifiers (e.g., userId, deviceId, accountId) without proper authorization checks. An attacker with a valid session can enumerate or brute-force these identifiers to access resources belonging to other users.

Example vulnerable endpoint:
GET /api/userService/v1/userProfile?userId=12345
If the server does not verify that the requesting user owns or is authorized to view userId=12345, an attacker can change the parameter to userId=12346 and retrieve another user’s profile, device list, or energy production data.

The impact includes:

• Unauthorized access to personal information (name, email, address, phone number).
• Exposure of solar device configurations and real-time energy data.
• Potential manipulation of device settings (e.g., inverter parameters) if the API also allows modification via IDOR.

Vulnerable vs. Patched Code

No specific code snippets are available. The patch likely involves adding server-side authorization checks to ensure that the authenticated user’s session token matches the resource owner before returning data. For example:

Vulnerable (pseudocode):

@app.route('/api/userService/v1/userProfile')
def get_user_profile():
    user_id = request.args.get('userId')
    user = db.query("SELECT * FROM users WHERE id = ?", user_id)
    return jsonify(user)

Patched (pseudocode):

@app.route('/api/userService/v1/userProfile')
def get_user_profile():
    user_id = request.args.get('userId')
    session_user_id = get_session_user_id(request)
    if session_user_id != user_id:
        return "Forbidden", 403
    user = db.query("SELECT * FROM users WHERE id = ?", user_id)
    return jsonify(user)

Exploitation & Lab Setup

Red Team

Prerequisites:

• Valid user account on iSolarCloud.
• Network access to the iSolarCloud API endpoints.

Exploitation Steps:

1. Authenticate and capture a valid session token (e.g., JWT or cookie).
2. Intercept a legitimate API request (e.g., fetching own profile).
3. Modify the userId or similar parameter to a different value (e.g., increment by 1).
4. Observe if the API returns data for the other user.
5. Automate enumeration using a script (e.g., Python with requests).

Example Python script (conceptual):

import requests

session = requests.Session()
session.headers.update({'Authorization': 'Bearer <valid_token>'})

for user_id in range(1000, 2000):
    r = session.get(f'https://isolarcloud.example.com/api/userService/v1/userProfile?userId={user_id}')
    if r.status_code == 200 and 'email' in r.json():
        print(f"Found user {user_id}: {r.json()}")

Blue Team

Detection:

• Monitor API logs for anomalous patterns: multiple sequential userId values from the same session.
• Alert on 200 responses to requests where userId does not match the authenticated user’s ID.
• Implement rate limiting on API endpoints that accept user identifiers.

Hunting:

• Search for logs where userId parameter values change rapidly within a short time window.
• Correlate with session tokens to identify potential enumeration.

Indicators of Compromise (IOCs)

• Network:

  • Unusual API calls to /api/userService/v1/userProfile (or similar) with varying userId parameters.
  • High frequency of 200 responses from the same source IP to different user IDs.

• Logs:

  • Repeated requests with sequential or brute-forced userId values.
  • Access to resources not owned by the authenticated user.

• File/Registry: None.

Detection Engineering

YARA Rule

rule CVE_2024_50693_IDOR_Enumeration {
    meta:
        description = "Detects potential IDOR enumeration against SunGrow iSolarCloud userService API"
        author = "Valters IT"
        date = "2025-01-01"
        reference = "CVE-2024-50693"
    strings:
        $api_path = "/api/userService/v1/userProfile" nocase
        $param_userId = "userId=" nocase
    condition:
        $api_path and $param_userId
}

Sigma Rule

title: SunGrow iSolarCloud IDOR Enumeration
id: 8a9b3c4d-5e6f-7a8b-9c0d-1e2f3a4b5c6d
status: experimental
description: Detects potential IDOR enumeration attempts against iSolarCloud userService API
author: Valters IT
date: 2025/01/01
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2024-50693
logsource:
    category: web
    product: iis
    service: application
detection:
    selection:
        cs-uri-query|contains: "/api/userService/v1/userProfile?userId="
    condition: selection
falsepositives:
    - Legitimate API usage with different user IDs (e.g., admin functions)
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2024-50693 SunGrow iSolarCloud IDOR Enumeration"; flow:to_server,established; content:"/api/userService/v1/userProfile"; http_uri; content:"userId="; http_uri; classtype:attempted-recon; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Apply the vendor’s October 31, 2024 remediation (contact SunGrow support if patch details are unclear).
2. If patching is not possible, implement a Web Application Firewall (WAF) rule to block requests with suspicious userId patterns (e.g., sequential numbers).
3. Enforce strict server-side authorization checks for all API endpoints that accept user or device identifiers.

Long-term:

• Conduct a full security audit of the iSolarCloud API for similar IDOR flaws.
• Implement role-based access control (RBAC) and ensure every API call validates ownership.
• Use unpredictable identifiers (e.g., UUIDs) instead of sequential integers.

Valters IT – Securing critical infrastructure through proactive threat intelligence.