CVE-2021-4418
Custom CSS, JS & PHP <= 2.0.7 - Cross-Site Request Forgery Bypass
The Custom CSS, JS & PHP plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 2.0.7. This is due to missing or incorrect nonce validation on the save() function. This makes it possible for unauthenticated attackers to save code snippets via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- None
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Custom CSS, JS & PHP <= 2.0.7 - Cross-Site Request Forgery Bypass
The Custom CSS, JS & PHP plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 2.0.7. This is due to missing or incorrect nonce validation on the save() function. This makes it possible for unauthenticated attackers to save code snippets via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.
- Record
CVE-2021-4418- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N - Weakness
- CWE-352
- Updated
- 2026-11-02
EUVDEUVD-2021-34245
The Custom CSS, JS & PHP plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 2.0.7. This is due to missing or incorrect nonce validation on the save() function. This makes it possible for unauthenticated attackers to save code snippets via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.
- Record
EUVD-2021-34245- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-j98c-6x58-jmvw
The Custom CSS, JS & PHP plugin for WordPress is vulnerable to Cross-Site Request Forgery in...
The Custom CSS, JS & PHP plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 2.0.7. This is due to missing or incorrect nonce validation on the save() function. This makes it possible for unauthenticated attackers to save code snippets via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.
- Record
GHSA-j98c-6x58-jmvw- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N - Weakness
- CWE-352
- Updated
- 2026-11-02
NVD
The Custom CSS, JS & PHP plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 2.0.7. This is due to missing or incorrect nonce validation on the save() function. This makes it possible for unauthenticated attackers to save code snippets via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.
- Record
CVE-2021-4418- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N - Weakness
- CWE-352
- 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-2021-4418 is a medium vulnerability (CVSS 4.3) in Flippercode Custom Css-js-php, published October 20, 2023. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.48%, the 41st percentile. No source names a fixed version.
References
wordfence.com/threat-intel/vulnerabilities/id/d21dc02f-789c-497e-9d01-02fa49bf9e30?source=cve
blog.nintechnet.com/25-wordpress-plugins-vulnerable-to-csrf-attacks
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plugins.trac.wordpress.org/browser/custom-css-js-php/trunk/modules/code/model.code.php
nvd.nist.gov/vuln/detail/CVE-2021-4418
github.com/advisories/GHSA-j98c-6x58-jmvw