CVE-2021-4422

CVE-2021-4422 is a medium-severity vulnerability in Wpexperts Post Smtp with a CVSS 3.x base score of 4.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-352.

Key facts

• Severity: Medium (CVSS 3.x base score 4.3)
• EPSS exploit prediction: 1% (42nd percentile)
• Actively exploited: Not listed in CISA KEV
• Weakness: CWE-352
• Affected product: Wpexperts Post Smtp
• Published: 2023-07-12
• Last modified: 2026-06-17

Description

The POST SMTP Mailer plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 2.0.20. This is due to missing or incorrect nonce validation on the handleCsvExport() function. This makes it possible for unauthenticated attackers to trigger a CSV export via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.

Frequently asked questions

What is CVE-2021-4422?

The POST SMTP Mailer plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 2.0.20. This is due to missing or incorrect nonce validation on the handleCsvExport() function. This makes it possible for unauthenticated attackers to trigger a CSV export via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.

How severe is CVE-2021-4422?

CVE-2021-4422 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity low, and availability none.

Is CVE-2021-4422 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (42nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-4422?

CVE-2021-4422 affects Wpexperts Post Smtp. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-4422?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-4422 published?

CVE-2021-4422 was published on 2023-07-12 and last updated on 2026-06-17.

References

• https://blog.nintechnet.com/25-wordpress-plugins-vulnerable-to-csrf-attacks/
• https://blog.nintechnet.com/more-wordpress-plugins-and-themes-vulnerable-to-csrf-attacks/
• https://blog.nintechnet.com/multiple-wordpress-plugins-fixed-csrf-vulnerabilities-part-1/
• https://blog.nintechnet.com/multiple-wordpress-plugins-fixed-csrf-vulnerabilities-part-2/
• https://blog.nintechnet.com/multiple-wordpress-plugins-fixed-csrf-vulnerabilities-part-3/
• https://blog.nintechnet.com/multiple-wordpress-plugins-fixed-csrf-vulnerabilities-part-4/
• https://blog.nintechnet.com/multiple-wordpress-plugins-fixed-csrf-vulnerabilities-part-5/
• https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=2473579%40post-smtp&new=2473579%40post-smtp&sfp_email=&sfph_mail=
• https://www.wordfence.com/threat-intel/vulnerabilities/id/e018ca7c-06dd-4d40-91d4-4ed188b8aaf2?source=cve

Affected products (1)

• cpe:2.3:a:wpexperts:post_smtp:*:*:*:*:*:wordpress:*:*

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