CyberSecBulletin
CVE-2025-3530NVD status: Deferred

Simple Shopping Cart: External Control of Assumed-Immutable Web Parameter

Published Updated By the CyberSecBulletin desk

CVE-2025-3530 is a high-severity external control of assumed-immutable web parameter vulnerability in Simple Shopping Cart from Mra13, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Simple Shopping Cart versions: 5.1.2 and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.54% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of Simple Shopping Cart you run against the affected versions below, and install the vendor's latest release.
  2. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
Mra13Simple Shopping Cart5.1.2 and earlierNot stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
NoneNo data is disclosed.
Integrity
HighData or code can be modified at will.
Availability
NoneAvailability is not affected.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N. Scored by CNA (wordfence.com).

Official description

The WordPress Simple Shopping Cart plugin for WordPress is vulnerable to product price manipulation in all versions up to, and including, 5.1.2. This is due to a logic flaw involving the inconsistent use of parameters during the cart addition process. The plugin uses the parameter 'product_tmp_two' for computing a security hash against price tampering while using 'wspsc_product' to display the product, allowing an unauthenticated attacker to substitute details from a cheaper product and bypass payment for a more expensive item.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: External Control of Assumed-Immutable Web Parameter

The web application does not sufficiently verify inputs that are assumed to be immutable but are actually externally controllable, such as hidden form fields.

How developers prevent this class of flaw

  • Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass allowlist validation schemes by introducing dangerous inputs after they have been checked.

More External Control of Assumed-Immutable Web Parameter vulnerabilities (CWE-472)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Simple Shopping Cart

All Simple Shopping Cart vulnerabilities

Recent External Control of Assumed-Immutable Web Parameter vulnerabilities

Spotted an error? Tell us.