Stop Referrer Spam <= 1.3.0 - Cross-Site Request Forgery via processParameters
Strategic Overview
- Status
- Patched in 1.3.1
- Affected Plugin
- Stop Referrer Spam
- Affected Version
<= 1.3.0- CVSS
- 5.4Medium
- Weakness type
- CWE-352 · Cross-Site Request Forgery (CSRF)
- CVE
CVE-2023-33207
At a glance
CVE-2023-33207 is a medium-severity Cross-Site Request Forgery (CSRF) vulnerability in the Stop Referrer Spam WordPress plugin, affecting versions <= 1.3.0. It carries a CVSS score of 5.4 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 1.3.1; sites on affected versions should update now. Disclosed May 2023, reported by Kévin Mosbahi (Mika).
Vulnerability Overview
The Stop Referrer Spam plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 1.3.0. This is due to insufficient nonce validation on the processParameters function. This makes it possible for unauthenticated attackers to refresh the spam blocklist and save custom URLs via a forged request granted they can trick a site administrator into performing an action such as clicking on a link. The issue was partially patched in version 1.3.0 but because nonce generation does not occur until the first time the admin page is visited, it is possible for an attacker to supply an empty nonce value which will successfully result in settings being saved if the administrator has not yet visited the plugin's admin page.
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.
CWE-352: Cross-Site Request Forgery (CSRF)
Reaching this weakness in Stop Referrer Spam <= 1.3.0 takes a caller who can reach the endpoint. Cross-site request forgery abuses the fact that browsers attach a victim's cookies to any request, so a state-changing action that only checks who you are, not whether you meant to act, can be triggered from another site.
An attacker who gets a logged-in user to load a crafted page can perform that action as them, with the impact scaling to whatever the victim's role is allowed to do. For Stop Referrer Spam the fix is 1.3.1: builds <= 1.3.0 are affected, anything from 1.3.1 onward is not.
Remediation
Update to version 1.3.1, or a newer patched version
How does WordSec protect against this?
The attempt arrives as an ordinary request to Stop Referrer Spam: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Stop Referrer Spam 1.3.1 closes this, and updating the plugin is the step that ends it.
- Firewall
- Alerts
External References
Vulnerability data © Defiant, Inc., provided under the Wordfence Intelligence T&C