CVE-2025-6688

Simple Payment 1.3.6 - 2.3.8 - Authentication Bypass to Admin

2025-06-26 00:00
kr0d

Strategic Overview

Status
Patched in 2.3.9
Affected Plugin
Simple Payment
Affected Version
1.3.6 – 2.3.8
CVSS
9.8Critical
Weakness type
CWE-288 · Authentication Bypass Using an Alternate Path or Channel
CVE
CVE-2025-6688
View all Simple Payment vulnerabilities

At a glance

CVE-2025-6688 is a critical-severity Authentication Bypass Using an Alternate Path or Channel vulnerability in the Simple Payment WordPress plugin, affecting versions 1.3.6 – 2.3.8. It carries a CVSS score of 9.8 (reachable over the network; low attack complexity; high confidentiality, integrity, availability impact). Exploitation requires no authentication. The issue is fixed in version 2.3.9; sites on affected versions should update now. Disclosed June 2025, reported by kr0d.

Vulnerability Overview

The Simple Payment plugin for WordPress is vulnerable to Authentication Bypass in versions 1.3.6 to 2.3.8. This is due to the plugin not properly verifying a user's identity prior to logging them in through the create_user() function. This makes it possible for unauthenticated attackers to log in as administrative users.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no privileges on the target site, and no interaction from a victim user. A successful exploit has high impact on confidentiality, integrity, availability — full site compromise territory.

CWE-288: Authentication Bypass Using an Alternate Path or Channel

Simple Payment 1.3.6 – 2.3.8 carries this weakness at create_user(), and reaching it takes a caller who can reach the endpoint. Authentication bypass through an alternate path means the application has a second route to a protected action that skips the checks the primary route performs.

The protection on the main path becomes irrelevant, because the attacker simply uses the route that never asks. For Simple Payment the fix is 2.3.9: builds 1.3.6 – 2.3.8 are affected, anything from 2.3.9 onward is not.

Remediation

Update to version 2.3.9, or a newer patched version

How does WordSec protect against this?

Because it turns on account access, WordSec's login security is the relevant layer: role-based two-factor, captcha and brute-force limits raise the cost of getting the account this needs. None of that substitutes for the fix: Simple Payment 2.3.9 closes this, and updating the plugin is the step that ends it.

  • Login Security
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2025-6688https://www.wordfence.com/threat-intel/vulnerabilities/id/8b4e2f87-e3ad-4f1b-b647-f5e5a49f691bhttps://nvd.nist.gov/vuln/detail/CVE-2025-6688

Related records

Vulnerability data © Defiant, Inc., provided under the Wordfence Intelligence T&C