CVE-2021-4451 - CVE House
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Status published Medium CVE-2021-4451

NinjaFirewall <= 4.3.3 - Authenticated PHAR Deserialization

Vulnerability Description

The NinjaFirewall plugin for WordPress is vulnerable to Authenticated PHAR Deserialization in versions up to, and including, 4.3.3. This allows authenticated attackers to perform phar deserialization on the server. This deserialization can allow other plugin or theme exploits if vulnerable software is present (WordPress, and NinjaFirewall).

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

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Credits & Attribution

The following person or organization is credited with identifying this vulnerability, as recorded in the NVD database:

  • Chloe Chamberland

References

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High 7.2

Affected Vendor

Affected Software

NinjaFirewall (WP Edition) – Advanced Security Plugin and Firewall
Vulnerable Versions:
0

Timeline

Official Publish: October 16th, 2024
Last Modified: April 8th, 2026
Added to House: July 21st, 2026

CVSS Vectors

V3: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H

Weaknesses (CWE)

CWE-502

MITRE ATT&CK TTPs

T1190 Exploit Public-Facing Application
Initial Access
T1059 Command and Scripting Interpreter
Execution
T1505.003 Web Shell
Persistence
T1105 Ingress Tool Transfer
Command and Control
T1068 Exploitation for Privilege Escalation
Privilege Escalation