CVE-2026-4563: MacCMS Authorization Bypass Vulnerability

CVE-2026-4563 Overview

A significant authorization bypass vulnerability has been identified in MacCMS up to version 2025.1000.4052. This vulnerability affects the order_info function within the file application/index/controller/User.php of the Member Order Detail Interface component. Through manipulation of the order_id argument, an authenticated attacker can bypass authorization controls and access order information belonging to other users. The vulnerability is remotely exploitable, and exploit details have been made publicly available.

Critical Impact

Authenticated attackers can bypass authorization controls to access sensitive order details belonging to other users, potentially exposing personal information and transaction data stored in the MacCMS system.

Affected Products

• MacCMS versions up to 2025.1000.4052
• MacCMS Member Order Detail Interface component
• Applications utilizing the application/index/controller/User.php file

Discovery Timeline

• 2026-03-23 - CVE-2026-4563 published to NVD
• 2026-03-23 - Last updated in NVD database

Technical Details for CVE-2026-4563

Vulnerability Analysis

This vulnerability is classified under CWE-285 (Improper Authorization). The flaw exists in the order_info function responsible for retrieving and displaying member order details. The function fails to properly validate whether the authenticated user has legitimate access to the requested order before returning the order information. This allows any authenticated user to view order details belonging to other users by manipulating the order_id parameter in their requests.

The attack can be initiated remotely over the network with low complexity. An attacker requires valid authentication credentials (low privileges) but does not need any user interaction to exploit the vulnerability. The primary impact is unauthorized disclosure of confidential order information, potentially including customer names, addresses, payment details, and purchase history.

Root Cause

The root cause of this vulnerability is improper authorization validation in the order_info function. The function accepts an order_id parameter and retrieves the corresponding order data without verifying that the authenticated user is the owner of that order. This classic Insecure Direct Object Reference (IDOR) pattern allows horizontal privilege escalation, where users can access resources belonging to other users at the same privilege level.

Attack Vector

The attack is performed remotely through the network interface. An authenticated attacker can exploit this vulnerability by directly manipulating the order_id parameter in HTTP requests to the Member Order Detail Interface endpoint. By iterating through different order_id values or using predictable identifiers, the attacker can enumerate and access order information belonging to other users.

The vulnerability mechanism operates as follows: When a user requests their order details, the application accepts an order_id parameter and queries the database for the matching order record. However, the application fails to verify that the requesting user's session is associated with the owner of that order. Technical details and proof-of-concept information can be found in the GitHub CVE Issue Tracker and VulDB #352400.

Detection Methods for CVE-2026-4563

Indicators of Compromise

• Unusual patterns of order detail requests from single user sessions accessing multiple unrelated order IDs
• Sequential or enumerated order_id parameter values in request logs
• High volume of requests to the Member Order Detail Interface from individual users
• Access log entries showing users retrieving order details at abnormal rates

Detection Strategies

• Implement logging and alerting for requests where the authenticated user ID does not match the owner of the requested order
• Monitor for parameter tampering patterns in order_id values within web application firewall logs
• Deploy anomaly detection rules to identify users accessing orders outside their normal patterns
• Review application logs for enumeration attempts against the order detail endpoint

Monitoring Recommendations

• Enable detailed access logging on the MacCMS Member Order Detail Interface endpoints
• Configure alerts for suspicious patterns of order ID parameter manipulation
• Implement rate limiting on order detail requests to slow down enumeration attempts
• Establish baseline user behavior metrics for order access patterns to detect anomalies

How to Mitigate CVE-2026-4563

Immediate Actions Required

• Upgrade MacCMS to a patched version when available from the vendor
• Review and audit the order_info function in application/index/controller/User.php to add proper authorization checks
• Implement server-side validation to verify the authenticated user owns the requested order before returning data
• Consider temporarily restricting access to the Member Order Detail Interface until a patch is applied

Patch Information

At the time of publication, specific patch information from the MacCMS vendor is not available. Administrators should monitor the official MacCMS channels for security updates. Additional technical details and tracking information are available through VulDB CTI #352400 and the VulDB Submission #775050.

Workarounds

• Add custom authorization logic to verify user ownership of orders before displaying details
• Implement web application firewall rules to detect and block suspicious order_id parameter manipulation
• Restrict access to the Member Order Detail Interface to trusted IP ranges where possible
• Enable additional authentication factors for accessing sensitive order information

# Example authorization check concept (implement in application code)
# Verify that the authenticated user's ID matches the order owner
# before returning order details in the order_info function
# user_id = get_authenticated_user_id()
# order = get_order_by_id(order_id)
# if order.owner_id != user_id:
#     return access_denied_response()