CVE-2025-3889: CWE-639 Authorization Bypass Through User-Controlled Key in mra13 Simple Shopping Cart
The WordPress Simple Shopping Cart plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 5.1.3 via the 'process_payment_data' due to missing validation on a user controlled key. This makes it possible for unauthenticated attackers to change the quantity of a product to a negative number, which subtracts the product cost from the total order cost. The attack will only work with Manual Checkout mode, as PayPal and Stripe will not process payments for a negative quantity.
AI Analysis
Technical Summary
The Simple Shopping Cart plugin for WordPress suffers from an authorization bypass vulnerability (CWE-639) caused by insufficient validation of a user-controlled key in the 'process_payment_data' function. This allows unauthenticated attackers to set product quantities to negative values, which subtracts from the total order cost. The issue affects all versions up to and including 5.1.3. Exploitation is limited to Manual Checkout mode because automated payment processors reject negative quantities.
Potential Impact
An attacker can reduce the total order cost by submitting negative product quantities, potentially allowing unauthorized discounts or free purchases when using Manual Checkout mode. There is no impact on confidentiality or availability, and the vulnerability does not affect automated payment methods like PayPal or Stripe. No known exploits are reported in the wild.
Mitigation Recommendations
No official patch or fix is currently available for this vulnerability. Users should avoid using Manual Checkout mode or restrict access to the affected plugin until a vendor-provided fix is released. Monitor the vendor's advisory channels for updates regarding remediation.
CVE-2025-3889: CWE-639 Authorization Bypass Through User-Controlled Key in mra13 Simple Shopping Cart
Description
The WordPress Simple Shopping Cart plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 5.1.3 via the 'process_payment_data' due to missing validation on a user controlled key. This makes it possible for unauthenticated attackers to change the quantity of a product to a negative number, which subtracts the product cost from the total order cost. The attack will only work with Manual Checkout mode, as PayPal and Stripe will not process payments for a negative quantity.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Simple Shopping Cart plugin for WordPress suffers from an authorization bypass vulnerability (CWE-639) caused by insufficient validation of a user-controlled key in the 'process_payment_data' function. This allows unauthenticated attackers to set product quantities to negative values, which subtracts from the total order cost. The issue affects all versions up to and including 5.1.3. Exploitation is limited to Manual Checkout mode because automated payment processors reject negative quantities.
Potential Impact
An attacker can reduce the total order cost by submitting negative product quantities, potentially allowing unauthorized discounts or free purchases when using Manual Checkout mode. There is no impact on confidentiality or availability, and the vulnerability does not affect automated payment methods like PayPal or Stripe. No known exploits are reported in the wild.
Mitigation Recommendations
No official patch or fix is currently available for this vulnerability. Users should avoid using Manual Checkout mode or restrict access to the affected plugin until a vendor-provided fix is released. Monitor the vendor's advisory channels for updates regarding remediation.
Technical Details
- Data Version
- 5.1
- Assigner Short Name
- Wordfence
- Date Reserved
- 2025-04-22T23:10:04.442Z
- Cisa Enriched
- true
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 682d9839c4522896dcbece31
Added to database: 5/21/2025, 9:09:13 AM
Last enriched: 4/9/2026, 5:25:18 PM
Last updated: 5/10/2026, 1:53:29 PM
Views: 98
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