CVE-2025-61546 is a security vulnerability identified in edu Business Solutions Print Shop Pro WebDesk version 18.34. The flaw exists in the /PSP/appNET/Store/CartV12.aspx/GetUnitPrice endpoint, which is responsible for calculating unit prices during the purchase process. The vulnerability arises because the application relies solely on client-side input validation to enforce quantity constraints. Attackers can bypass these controls and submit negative quantities for items, causing the system to process transactions with negative values. This can lead to financial discrepancies such as unauthorized credits, refunds, or manipulation of accounting records. The vulnerability does not require authentication or user interaction, making it remotely exploitable by any attacker aware of the endpoint. No CVSS score has been assigned yet, and no patches or known exploits have been reported. The root cause is the lack of server-side validation to verify that quantities are positive integers before processing. This type of vulnerability can undermine the integrity of financial transactions and potentially lead to monetary losses or fraud. Organizations using this version of Print Shop Pro WebDesk should urgently review their input validation mechanisms and transaction logging to detect and prevent abuse.

For European organizations, the primary impact of this vulnerability is financial loss due to manipulated transactions. Attackers exploiting the negative quantity input can create unauthorized credits or refunds, disrupting accounting and financial reporting. This can also lead to reputational damage if customers or partners become aware of fraudulent activities. Additionally, exploitation could undermine trust in the affected organization's e-commerce or internal purchasing systems. The vulnerability may also complicate compliance with financial regulations such as GDPR and local financial auditing standards, especially if financial data integrity is compromised. Organizations in sectors heavily reliant on print services or using edu Business Solutions software for order processing are at higher risk. The lack of authentication requirement and remote exploitability increase the threat level, potentially allowing widespread abuse if not mitigated promptly.

1. Implement strict server-side validation to ensure that all quantity inputs are positive integers before processing any transaction. 2. Audit and monitor transaction logs for unusual patterns such as negative quantities or unexpected credits/refunds. 3. Apply input sanitization and validation at multiple layers, including API endpoints and backend services. 4. Restrict access to the /PSP/appNET/Store/CartV12.aspx/GetUnitPrice endpoint using authentication and authorization controls where possible. 5. Develop and deploy patches or updates from the vendor as soon as they become available. 6. Conduct regular security assessments and penetration testing focusing on input validation and financial transaction workflows. 7. Educate staff and developers about the risks of relying solely on client-side validation. 8. Consider implementing anomaly detection systems to flag suspicious transaction activities in real-time.