CVE-2021-4425
Defender Security <= 2.4.6 - Cross-Site Request Forgery Bypass
The Defender Security plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 2.4.6. This is due to missing or incorrect nonce validation on the verify_otp_login_time() function. This makes it possible for unauthenticated attackers to verify a one time login 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
4.3
Defender Security <= 2.4.6 - Cross-Site Request Forgery Bypass
The Defender Security plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 2.4.6. This is due to missing or incorrect nonce validation on the verify_otp_login_time() function. This makes it possible for unauthenticated attackers to verify a one time login via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.
- Record
CVE-2021-4425- 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-2021-34252
4.3
The Defender Security plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 2.4.6. This is due to missing or incorrect nonce validation on the verify_otp_login_time() function. This makes it possible for unauthenticated attackers to verify a one time login via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.
- Record
EUVD-2021-34252- 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-wmpx-27x6-m5w5
4.3
The Defender Security plugin for WordPress is vulnerable to Cross-Site Request Forgery in...
The Defender Security plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 2.4.6. This is due to missing or incorrect nonce validation on the verify_otp_login_time() function. This makes it possible for unauthenticated attackers to verify a one time login via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.
- Record
GHSA-wmpx-27x6-m5w5- 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
4.3
The Defender Security plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 2.4.6. This is due to missing or incorrect nonce validation on the verify_otp_login_time() function. This makes it possible for unauthenticated attackers to verify a one time login via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.
- Record
CVE-2021-4425- 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-2021-4425 is a medium vulnerability (CVSS 4.3) in Wpmudev Defender Security, published July 12, 2023. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.56%, the 47th percentile. No source names a fixed version.
References
wordfence.com/threat-intel/vulnerabilities/id/e772fbbe-33d5-46fa-a041-ab07d3f9318f?source=cve
blog.nintechnet.com/25-wordpress-plugins-vulnerable-to-csrf-attacks
blog.nintechnet.com/more-wordpress-plugins-and-themes-vulnerable-to-csrf-attacks
blog.nintechnet.com/multiple-wordpress-plugins-fixed-csrf-vulnerabilities-part-3
blog.nintechnet.com/multiple-wordpress-plugins-fixed-csrf-vulnerabilities-part-2
blog.nintechnet.com/multiple-wordpress-plugins-fixed-csrf-vulnerabilities-part-1
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blog.nintechnet.com/multiple-wordpress-plugins-fixed-csrf-vulnerabilities-part-5
blog.nintechnet.com/multiple-wordpress-plugins-fixed-csrf-vulnerabilities-part-4
plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=2473684%40defender-security&new=2473684%40defender-security&sfp_email=&sfph_mail=
nvd.nist.gov/vuln/detail/CVE-2021-4425
github.com/advisories/GHSA-wmpx-27x6-m5w5