CVE-2025-61546: Print Shop Pro WebDesk RCE Vulnerability

CVE-2025-61546 Overview

A business logic vulnerability exists in edu Business Solutions Print Shop Pro WebDesk version 18.34 that allows remote attackers to create financial discrepancies through the shopping cart functionality. The vulnerability is located in the /PSP/appNET/Store/CartV12.aspx/GetUnitPrice endpoint, which fails to properly validate quantity values submitted by users.

This flaw enables attackers to purchase items with negative quantity values, effectively bypassing intended pricing controls and potentially resulting in financial manipulation. The root cause stems from the application's reliance on client-side input validation controls without corresponding server-side enforcement.

Critical Impact

Remote attackers can manipulate financial transactions by submitting negative quantities, potentially creating credits, refunds, or pricing discrepancies that result in financial loss for organizations using this e-commerce platform.

Affected Products

• edu Business Solutions Print Shop Pro WebDesk version 18.34

Discovery Timeline

• 2026-01-08 - CVE CVE-2025-61546 published to NVD
• 2026-01-08 - Last updated in NVD database

Technical Details for CVE-2025-61546

Vulnerability Analysis

This vulnerability is classified as a Business Logic Error where the application fails to enforce proper input validation on the server side. The /PSP/appNET/Store/CartV12.aspx/GetUnitPrice endpoint accepts quantity parameters that directly influence pricing calculations without adequate bounds checking.

When a user submits a cart request with a negative quantity value, the server-side pricing logic processes this value without rejection. This can result in negative total prices, effectively converting a purchase transaction into a credit or refund scenario. The vulnerability demonstrates a classic case of insufficient server-side validation where developers relied solely on client-side JavaScript validation that can be easily bypassed.

The impact extends beyond simple pricing errors—attackers could potentially exploit this flaw to generate credits on their accounts, manipulate inventory systems, or create accounting discrepancies that may go unnoticed in automated financial reconciliation processes.

Root Cause

The fundamental issue is the application's reliance on client-side input validation controls without implementing corresponding server-side validation. Client-side validation can be easily bypassed by intercepting and modifying HTTP requests using browser developer tools, proxy applications like Burp Suite, or custom scripts.

The /PSP/appNET/Store/CartV12.aspx/GetUnitPrice endpoint processes quantity values directly in pricing calculations without verifying that the submitted value is a positive integer within acceptable business constraints. This architectural weakness allows malicious input to propagate through the application's business logic layer.

Attack Vector

An attacker can exploit this vulnerability by intercepting the legitimate cart request and modifying the quantity parameter to a negative value before it reaches the server. The attack can be performed remotely without authentication (depending on the application's access controls) and requires minimal technical skill.

The typical attack flow involves:

1. Adding a legitimate item to the shopping cart through the normal user interface
2. Intercepting the HTTP POST request to the GetUnitPrice endpoint
3. Modifying the quantity parameter from a positive value to a negative value
4. Forwarding the modified request to the server
5. Observing the resulting negative price calculation that creates a financial discrepancy

Technical details and proof-of-concept information are available in the GitHub PoC Repository.

Detection Methods for CVE-2025-61546

Indicators of Compromise

• HTTP POST requests to /PSP/appNET/Store/CartV12.aspx/GetUnitPrice containing negative numeric values in quantity parameters
• Transaction logs showing negative quantities or negative total prices
• Financial reconciliation reports with unexpected credits or discrepancies
• Anomalous patterns in shopping cart activity showing items with quantity values less than or equal to zero

Detection Strategies

• Implement web application firewall (WAF) rules to detect and block requests containing negative quantity values in POST parameters targeting cart endpoints
• Configure application-level logging to capture all quantity values submitted to pricing endpoints for anomaly analysis
• Deploy real-time transaction monitoring to alert on any orders with negative quantities or negative total amounts
• Enable audit logging on the Print Shop Pro WebDesk application to track all pricing calculations and cart modifications

Monitoring Recommendations

• Review transaction logs regularly for orders containing negative quantity values or resulting in negative totals
• Set up automated alerts for financial transactions that fall outside expected bounds (e.g., negative amounts, unusually large credits)
• Monitor for unusual patterns of requests to the GetUnitPrice endpoint, particularly from single IP addresses or sessions
• Implement integrity checks on financial reports to detect discrepancies that may indicate exploitation

How to Mitigate CVE-2025-61546

Immediate Actions Required

• Contact edu Business Solutions to determine if a security patch is available for Print Shop Pro WebDesk version 18.34
• Implement server-side input validation to reject any quantity values that are less than or equal to zero
• Deploy WAF rules to block requests with negative quantity parameters at the network perimeter
• Review recent transaction logs for evidence of exploitation and investigate any suspicious financial discrepancies

Patch Information

No official vendor patch information is currently available in the CVE data. Organizations should contact edu Business Solutions directly for guidance on available security updates or hotfixes. Monitor the vendor's security advisories for updates regarding this vulnerability.

Additional technical details can be found in the GitHub PoC Repository.

Workarounds

• Implement server-side input validation in the application code or through a reverse proxy to ensure quantity values are positive integers greater than zero
• Deploy a web application firewall (WAF) with custom rules to filter requests containing negative numeric values in cart-related parameters
• Restrict access to the Print Shop Pro WebDesk application to trusted networks or authenticated users only until a patch is available
• Consider temporarily disabling the affected endpoint if the business impact of the vulnerability outweighs the operational need for the functionality

Server-side validation should enforce that all quantity parameters are positive integers before processing pricing calculations. Organizations should implement defense-in-depth by combining input validation at multiple layers including the application, middleware, and network perimeter.