CVE-2021-39341
published 2021-11-01CVE-2021-39341: The OptinMonster WordPress plugin is vulnerable to sensitive information disclosure and unauthorized setting updates due to insufficient authorization…
PriorityP179high8.2CVSS 3.1
AVNACLPRNUINSUCHILAN
ITWEXPLOITVulnCheck KEV
Exploited in the wild
EPSS
23.27%
97.5th percentile
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.
Affected
2 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| optinmonster | optinmonster | <= 2.6.4 | — |
| optinmonster | optinmonster | 2.6.4 – 2.6.4 | — |
Detection & IOCsextracted from sources · hover to see the quote
url/wp-json/omapp/v1/support
- →Send an OPTIONS request (with X-HTTP-Method-Override: GET) to /wp-json/omapp/v1/support and look for 'PHP Version', 'OptinMonster', '"functions.php"', and 'Server Info' all present in the response body — this confirms the unprotected REST API endpoint is exposed.
- →Response body match (all four strings must be present simultaneously): 'PHP Version', 'OptinMonster', '"functions.php"', 'Server Info' — indicates sensitive server/plugin configuration disclosure via the unprotected endpoint.
- →The Referer header 'https://wp.app.optinmonster.test' is used in the exploit request to bypass the logged_in_or_has_api_key authorization check on the REST API endpoint.
- →The vulnerable function is logged_in_or_has_api_key in OMAPI/RestApi.php; audit WordPress sites for this plugin version ≤ 2.6.4 and monitor REST API access logs for unauthenticated requests to /wp-json/omapp/ routes. ↗
- ·The exploit requires only a single unauthenticated HTTP request (max-request: 1) with an X-HTTP-Method-Override header, making it trivially scriptable at scale against any WordPress site running OptinMonster ≤ 2.6.4.
- ·The vulnerability affects all OptinMonster WordPress plugin versions up to and including 2.6.4; version 2.6.5 contains the fix. ↗
- ·EPSS score of 0.44317 (97.564th percentile) indicates very high likelihood of exploitation in the wild; prioritize patching accordingly.
CVSS provenance
nvdv3.18.2HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
nvdv2.06.4MEDIUMAV:N/AC:L/Au:N/C:P/I:P/A:N
vulncheck8.2HIGH
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GHSA
GHSA-whcc-jgf3-q7pm: The OptinMonster WordPress plugin is vulnerable to sensitive information disclosure and unauthorized setting updates due to insufficient authorization
ghsa_unreviewed·2022-05-24
CVE-2021-39341 [HIGH] CWE-285 GHSA-whcc-jgf3-q7pm: The OptinMonster WordPress plugin is vulnerable to sensitive information disclosure and unauthorized setting updates due to insufficient authorization
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.
VulnCheck
optinmonster optinmonster Improper Authorization
vulncheck·2021·CVSS 8.2
CVE-2021-39341 [HIGH] optinmonster optinmonster Improper Authorization
optinmonster optinmonster Improper Authorization
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.
Affected: optinmonster optinmonster
Required Action: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.
Exploitation References: https://patchstack.com/database/vulnerability/optinmonster/wordpress-optinmonster-plugin-2-6-4-unprotected-rest-api-to-sensitive-information-disclosure-a
No detection rules found.
Nuclei
OptinMonster Plugin < 2.6.5 - Unprotected REST-API
nuclei·CVSS 8.2
CVE-2021-39341 [HIGH] OptinMonster Plugin < 2.6.5 - Unprotected REST-API
OptinMonster Plugin < 2.6.5 - Unprotected REST-API
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.
Template:
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 ~/OMAP
https://plugins.trac.wordpress.org/browser/optinmonster/trunk/OMAPI/RestApi.php?rev=2606519#L1460https://wordfence.com/vulnerability-advisories/#CVE-2021-39341https://www.wordfence.com/blog/2021/10/1000000-sites-affected-by-optinmonster-vulnerabilities/https://plugins.trac.wordpress.org/browser/optinmonster/trunk/OMAPI/RestApi.php?rev=2606519#L1460https://wordfence.com/vulnerability-advisories/#CVE-2021-39341https://www.wordfence.com/blog/2021/10/1000000-sites-affected-by-optinmonster-vulnerabilities/
2021-11-01
Published
Exploited in the wild