VulnCrest
Search
Create account
Report an incident
Radar sectionsDatabase
Check my site
WordPress plugin

OptinMonster <= 2.6.4 — Unprotected REST-API Endpoints

CVE-2021-39341Published · Updated

Action summary

Affected: ≤2.6.4Update to 2.6.5 or newer

All remediation steps
Watch plugin
Severity
High8.2
CVSS
8.2
CVSS 3.1 · CNA (Wordfence)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
What does this vector mean?
AV:N Attack vector
Network
AC:L Attack complexity
Low
PR:N Privileges required
None
UI:N User interaction
None
S:U Scope
Unchanged
C:H Confidentiality
High
I:L Integrity
Low
A:N Availability
None
Weakness
CWE-285 Improper Authorization
Required access
No account needed
Exploit prediction (EPSS)
No score
CISA KEV
Not listed
On this page8

Am I affected?

Popup Builder & Popup Maker for WordPress – OptinMonster Email Marketing and Lead Generation optinmonster

  1. Affected≤ 2.6.4
  2. Patched in2.6.5

Update to 2.6.5 or newer.

You are affected if you run ≤ 2.6.4. Version 2.6.5 and later are not affected by this issue.

  • Check your version: in wp-admin go to Plugins → Installed Plugins and read the version under Popup Builder & Popup Maker for WordPress – OptinMonster Email Marketing and Lead Generation.
  • No admin access? Run a passive check of your site. It reads public files only.
  • No account is needed to exploit this. Treat any exposed site on an affected version as at risk.

What to do

  1. Update to version 2.6.5, or a newer patched version
  2. Rotate administrator passwords and application secrets if the site ran a vulnerable version while publicly reachable.
  3. Watch Popup Builder & Popup Maker for WordPress – OptinMonster Email Marketing and Lead Generation to get an email when the next vulnerability is published.

Advisory

Source description from Wordfence Intelligence, credited to Chloe Chamberland.

The OptinMonster WordPress plugin is vulnerable to sensitive information disclosure and unauthorized setting updates due to insufficient authorization validation via the logged_in_or_has_api_key function in the ~/OMAPI/RestApi.php file that can used to exploit inject malicious web scripts on sites with the plugin installed. This affects versions up to, and including, 2.6.4.

Exploits & references

Proof-of-concept & detection

No public proof-of-concept or detection template is known for this vulnerability.

Advisories & patches

More in Popup Builder & Popup Maker for WordPress – OptinMonster Email Marketing and Lead Generation

All 6
More vulnerabilities in Popup Builder & Popup Maker for WordPress – OptinMonster Email Marketing and Lead Generation
SeverityVulnerabilityCVEPublished
Medium6.4Authenticated (Contributor+) Stored Cross-Site Scripting
≤2.16.1Update to 2.16.2
CVE-2024-4045
Medium4.3Cross-Site Request Forgery to Notice Dismissal
≤2.15.3Update to 2.16.0
CVE-2024-33691
Medium4.3 Authenticated (Subscriber+) Sensitive Information Disclosure via Shortcode
≤2.12.1Update to 2.12.2
CVE-2023-0772
Medium6.1Reflected Cross-Site Scripting
≤2.6.0Update to 2.6.1
CVE-2021-39325
Medium5.3Remote Code Execution
<1.1.4.6Update to 1.1.4.6
CVE-2016-10996

Timeline

  1. CVE published

    Severity high, CVSS 8.2

  2. Record last updated

Sources & licenses

Wordfence record
Vulnerability data
Wordfence Intelligence. Copyright 2012-2026 Defiant Inc. Licensed under the CC BY-SA 4.0.
CVE® identifiers
Copyright 1999-2026 The MITRE Corporation. Used under the CVE Program. CVE® is a registered trademark of The MITRE Corporation.
CVSS / CWE
National Vulnerability Database (NVD), shown unmodified. This product uses the NVD API but is not endorsed or certified by the NVD.
VulnCrest content
Summary, remediation guidance and page layout © VulnCrest. Not sourced from NVD.

How we use these sources

Search VulnCrest Radar

Jump to

Are you sure?