What is the CVSS score of CVE-2021-4387?

CVE-2021-4387 has a CVSS 3.1 base score of 4.3 (Medium). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N. EPSS exploitation probability: 0.1%.

Is there a public PoC exploit available for CVE-2021-4387?

Yes, a public proof-of-concept exploit is available for CVE-2021-4387. Prioritise patching immediately. EPSS: 0.1%.

Opal Estate CVE-2021-4387

MEDIUM

Cross-Site Request Forgery (CSRF) (CWE-352)

2023-07-01 security@wordfence.com

WordPress CSRF Opal Estate

4.3

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

4.3 MEDIUM

AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

None

Integrity

Low

Availability

None

Lifecycle Timeline

PoC Detected

Apr 08, 2026 - 17:16 vuln.today

Public exploit code

CVE Published

Jul 01, 2023 - 04:15 nvd

MEDIUM 4.3

DescriptionCVE.org

The Opal Estate plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 1.6.11. This is due to missing or incorrect nonce validation on the opalestate_set_feature_property() and opalestate_remove_feature_property() functions. This makes it possible for unauthenticated attackers to set and remove featured properties via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.

AnalysisAI

The Opal Estate plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 1.6.11. Rated medium severity (CVSS 4.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.

Technical ContextAI

This vulnerability is classified as Cross-Site Request Forgery (CSRF) (CWE-352), which allows attackers to trick authenticated users into performing unintended actions. The Opal Estate plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 1.6.11. This is due to missing or incorrect nonce validation on the opalestate_set_feature_property() and opalestate_remove_feature_property() functions. This makes it possible for unauthenticated attackers to set and remove featured properties via a forged request granted they can trick a site administrator into performing an action such as clicking on a link. Affected products include: Wpopal Opal Estate.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Implement anti-CSRF tokens, validate Origin/Referer headers, use SameSite cookie attribute.