WordPress Single Sign-On (SSO) - Multiple Versions - Incorrect Authorization to Sensitive Information Exposure
Strategic Overview
- Status
- Patched in 18.5.4
- Affected Plugin
- WordPress Single Sign-On (SSO) - Single Site Standard
- Affected Version
<= 18.5.3- CVSS
- 5.3Medium
- Weakness type
- CWE-863 · Incorrect Authorization
- CVE
CVE-2025-6003
At a glance
CVE-2025-6003 is a medium-severity Incorrect Authorization vulnerability in the WordPress Single Sign-On (SSO) - Single Site Standard WordPress plugin, affecting versions <= 18.5.3. It carries a CVSS score of 5.3 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 18.5.4; sites on affected versions should update now. Disclosed June 2025, reported by Israël Hallé (Flare).
Vulnerability Overview
The WordPress Single Sign-On (SSO) plugin for WordPress is vulnerable to unauthorized access due to a misconfigured capability check on a function in all versions up to, and including, the *.5.3 versions of the plugin. This makes it possible for unauthenticated attackers to extract sensitive data including site content that has been restricted to certain users and/or roles.
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.
CWE-863: Incorrect Authorization
Reaching this weakness in WordPress Single Sign-On (SSO) - Single Site Standard <= 18.5.3 takes a caller who can reach the endpoint. Incorrect authorization means a permission check exists but evaluates the wrong thing, so it passes for callers it was meant to stop.
The action runs for users the code intended to exclude, with the same effect as having no check at all. For WordPress Single Sign-On (SSO) - Single Site Standard the fix is 18.5.4: builds <= 18.5.3 are affected, anything from 18.5.4 onward is not.
Remediation
Update to version 18.5.4, 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: WordPress Single Sign-On (SSO) - Single Site Standard 18.5.4 closes this, and updating the plugin is the step that ends it.
- Login Security
- Alerts
External References
Related records
Other vulnerabilities in WordPress Single Sign-On (SSO) - Single Site Standard
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