# Security & Malware scan by CleanTalk <= 2.189 - Unauthenticated Rate Limit Bypass via User-Agent Header

- **ID:** WPSEC-2026-1008
- **Plugin:** Security Plugin, Firewall & Malware Scanner with Auto Removal (`security-malware-firewall`), https://wordpress.org/plugins/security-malware-firewall/
- **Affected versions:** from 2.176 before 2.190
- **Fixed in:** 2.190 (Update to 2.190 or later.)
- **Severity:** Medium 5.3 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N)
- **Weakness:** CWE-307
- **Usage among sites WPSec scans:** plugin Low, affected versions Low (as of 2026-10-15)
- **Attack surface analysis:** https://attacksurface.wpsec.com/plugin/security-malware-firewall
- **Fix released:** 2026-10-14
- **Published:** 2026-10-15
- **URL:** https://wpsec.com/vuln/WPSEC-2026-1008/

## Description

The Security Plugin, Firewall & Malware Scanner with Auto Removal plugin for WordPress is vulnerable to a rate limit bypass via the User-Agent header in all versions up to, and including, 2.189, due to the plugin's rate limiter building its counter key from the client-supplied User-Agent header together with the IP address, and updating the counter non-atomically. This makes it possible for unauthenticated attackers to evade the plugin's request rate limits, including the limits on two-factor authentication code submissions and the leaked-password change form, by sending a different User-Agent with each request. This weakens the plugin's brute-force protection.

## References

- https://wpsec.com/vuln/WPSEC-2026-1008/
- https://plugins.svn.wordpress.org/security-malware-firewall/tags/2.190/
- https://wordpress.org/plugins/security-malware-firewall/

Source: WPSec, https://wpsec.com/vuln/WPSEC-2026-1008/

License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Free to use, share and adapt, also commercially, if you credit WPSec and link to this advisory.