CVE-2023-51682

MC4WP <= 4.9.9 - Missing Authorization via listen

2023-12-27 00:00

Strategic Overview

Status: Patched in 4.9.10
Affected Plugin: MC4WP: Mailchimp for WordPress
Affected Version: <= 4.9.9
CVSS: 5.3Medium
Weakness type: CWE-862 · Missing Authorization
CVE: CVE-2023-51682

View all MC4WP: Mailchimp for WordPress vulnerabilities

At a glance

CVE-2023-51682 is a medium-severity Missing Authorization vulnerability in the MC4WP WordPress plugin, affecting versions <= 4.9.9. It carries a CVSS score of 5.3 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 4.9.10; sites on affected versions should update now. Disclosed December 2023, reported by Rafie Muhammad.

Vulnerability Overview

The MC4WP plugin for WordPress is vulnerable to unauthorized access of data due to a missing capability check on the 'listen' function in versions up to, and including, 4.9.9. This makes it possible for unauthenticated attackers to preview unpublished forms.

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.

CWE-862: Missing Authorization

MC4WP <= 4.9.9 carries this weakness at listen, and reaching it takes a caller who can reach the endpoint. A missing authorization check means a function is reachable by anyone who can reach the endpoint, because the code never asks whether the caller is allowed to perform the action.

Any user who can reach the endpoint gets to run an action reserved for higher-privileged roles, from reading protected data to changing settings or content. For MC4WP the fix is 4.9.10: builds <= 4.9.9 are affected, anything from 4.9.10 onward is not.

Remediation

Update to version 4.9.10, 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: MC4WP 4.9.10 closes this, and updating the plugin is the step that ends it.

Login Security
Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2023-51682 https://www.wordfence.com/threat-intel/vulnerabilities/id/4f289527-3a89-4db9-887d-fb0980848734 https://nvd.nist.gov/vuln/detail/CVE-2023-51682

Related records

Same weakness class

6.5CVE-2026-1781: MC4WP Unauthenticated Arbitrary Subscription DeletionCVE-2026-1781

Other vulnerabilities in MC4WP: Mailchimp for WordPress

CVSS Vector

5.3

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

Base

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone
User InteractionNone
ScopeUnchanged
ConfidentialityLow
IntegrityNone
AvailabilityNone

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