Anti-Malware Security and Brute-Force Firewall <= 4.20.93 - Reflected Cross-Site Scripting
Strategic Overview
- Status
- Patched in 4.20.94
- Affected Plugin
- Anti-Malware Security and Brute-Force Firewall
- Affected Version
< 4.20.94- CVSS
- 6.1Medium
- Weakness type
- CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
- CVE
CVE-2021-25101
At a glance
CVE-2021-25101 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the Anti-Malware Security and Brute-Force Firewall WordPress plugin, affecting versions < 4.20.94. It carries a CVSS score of 6.1 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 4.20.94; sites on affected versions should update now. Disclosed January 2022, reported by ZhongFu Su.
Vulnerability Overview
The Anti-Malware Security and Brute-Force Firewall WordPress plugin before 4.20.94 does not sanitise and escape the POST data before outputting it back in attributes of an admin page, leading to a Reflected Cross-Site scripting. Due to the presence of specific parameter value, available to admin users, this can only be exploited by an admin against another admin user.
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-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Reaching this weakness in Anti-Malware Security and Brute-Force Firewall < 4.20.94 takes a caller who can reach the endpoint. Cross-site scripting happens when input from a request is written into a page without being escaped for the context it lands in, so the browser parses attacker-supplied text as markup or script.
Injected script runs with the privileges of whoever views the affected page, which is how these flaws turn into administrator session theft, silent account creation or persistent backdoors in page content. For Anti-Malware Security and Brute-Force Firewall the fix is 4.20.94: builds < 4.20.94 are affected, anything from 4.20.94 onward is not.
Remediation
Update to version 4.20.94, or a newer patched version
How does WordSec protect against this?
The attempt arrives as an ordinary request to Anti-Malware Security and Brute-Force Firewall: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Anti-Malware Security and Brute-Force Firewall 4.20.94 closes this, and updating the plugin is the step that ends it.
- Firewall
- Alerts
External References
Related records
Same weakness class
- 7.2CVE-2026-57691: Anti-Malware Security and Brute-Force… Stored XSS
CVE-2026-57691 - 7.2Anti-Malware Security and Brute-Force Firewall <= 4.15.17 XSS
- 6.1CVE-2022-0953: Anti-Malware Security and Brute-Force… Reflected XSS
CVE-2022-0953 - 6.1CVE-2022-2599: Anti-Malware Security and Brute-Force… Reflected XSS
CVE-2022-2599
Other vulnerabilities in Anti-Malware Security and Brute-Force Firewall
- 9.0CVE-2024-22144: Anti-Malware Security and Brute-Force Firewall RCE
CVE-2024-22144 - 7.5CVE-2026-39478: Anti-Malware Security… PHP Object Injection
CVE-2026-39478 - 7.2CVE-2022-4327: Anti-Malware Security… PHP Object Injection
CVE-2022-4327 - 6.5CVE-2025-11705: Anti-Malware Security… Authenticated (Subscriber+)
CVE-2025-11705 - 6.1Anti-Malware Security and Brute-Force Firewall <= 4.15.22 XSS
- 3.1Anti-Malware Security and Brute-Force Firewall <= 4.15.22 CSRF
Vulnerability data © Defiant, Inc., provided under the Wordfence Intelligence T&C