CVE-2021-4451
NinjaFirewall <= 4.3.3 - Authenticated PHAR Deserialization
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).
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- High
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
NinjaFirewall <= 4.3.3 - Authenticated PHAR Deserialization
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).
- Record
CVE-2021-4451- CVSS 3.1
- 6.6 Medium
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-502
- Updated
- 2026-11-02
EUVDEUVD-2021-34636
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).
- Record
EUVD-2021-34636- CVSS 3.1
- 6.6 Medium
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-pgv2-9j82-2qcq
The NinjaFirewall plugin for WordPress is vulnerable to Authenticated PHAR Deserialization in...
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).
- Record
GHSA-pgv2-9j82-2qcq- CVSS 3.1
- 6.6 Medium
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-502
- Updated
- 2026-11-02
NVD
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).
- Record
CVE-2021-4451- CVSS 3.1
- 6.6 Medium
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H - CVSS 3.1
- 7.2 High
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-502
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-4451 is a medium vulnerability (CVSS 6.6) in Nintechnet Ninjafirewall, published October 16, 2024. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.64%, the 50th percentile. No source names a fixed version.