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Fencer Vulns
medium 4.3

CVE-2021-4387 json

Opal Estate <= 1.6.11 - Cross-Site Request Forgery Bypass

published 2023-07-01 3 y ago modified 2026-06-17 4 mo ago also EUVD-2021-34214

cvss
4.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 47%
public exploits
0
none known

Summary

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.

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.58% chance of exploitation in the next 30 days, higher than 47% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • blog.nintechnet.com https://blog.nintechnet.com/multiple-wordpress-plugins-fixed-csrf-vulnerabilities-part-5/ referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
NVD 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Affected products

  • wpopal Opal Estate

Classification

Weakness
  • CWE-352 Cross-Site Request Forgery
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.