CVE-2021-39341

OptinMonster <= 2.6.4 - Unprotected REST-API Endpoints

2021-11-01 09:02

Strategic Overview

Status: Patched in 2.6.5
Affected Plugin: Popup Builder & Popup Maker for WordPress – OptinMonster Email Marketing and Lead Generation
Affected Version: <= 2.6.4
CVSS: 8.2High
Weakness type: CWE-285 · Improper Authorization
CVE: CVE-2021-39341

View all Popup Builder & Popup Maker for WordPress – OptinMonster Email Marketing and Lead Generation vulnerabilities

At a glance

CVE-2021-39341 is a high-severity Improper Authorization vulnerability in the Popup Builder & Popup Maker for WordPress WordPress plugin, affecting versions <= 2.6.4. It carries a CVSS score of 8.2 (reachable over the network; low attack complexity; high confidentiality impact). Exploitation requires no authentication. The issue is fixed in version 2.6.5; sites on affected versions should update now. Disclosed November 2021, reported by Chloe Chamberland.

Vulnerability Overview

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.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no privileges on the target site, and no interaction from a victim user. A successful exploit has high impact on confidentiality.

CWE-285: Improper Authorization

Reaching this weakness in Popup Builder & Popup Maker for WordPress <= 2.6.4 takes a caller who can reach the endpoint. Improper authorization means a permission check exists but does not cover the case being exercised, so a caller who is allowed to do one thing is allowed to do a neighbouring thing as well.

A lower-privileged account performs an action reserved for a higher one, which on a multi-author or membership site means an ordinary user reaching administrative behaviour. For Popup Builder & Popup Maker for WordPress the fix is 2.6.5: builds <= 2.6.4 are affected, anything from 2.6.5 onward is not.

Remediation

Update to version 2.6.5, or a newer patched version

How does WordSec protect against this?

Because it turns on account access, WordSec's login security is the relevant layer: role-based two-factor, captcha and brute-force limits raise the cost of getting the account this needs. None of that substitutes for the fix: Popup Builder & Popup Maker for WordPress 2.6.5 closes this, and updating the plugin is the step that ends it.

Login Security
Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2021-39341 https://www.wordfence.com/threat-intel/vulnerabilities/id/77eb40c2-735a-49f2-9d07-5cf7535bd722 https://nvd.nist.gov/vuln/detail/CVE-2021-39341

Related records

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

CVSS Vector

8.2

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N

Base

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone
User InteractionNone
ScopeUnchanged
ConfidentialityHigh
IntegrityLow
AvailabilityNone

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