CVE-2023-32517

MailChimp Subscribe Forms <= 4.0.9.3 - Open Redirect

2023-05-10 00:00
minhtuanact

Strategic Overview

Status
Patched in 4.0.9.4
Affected Plugin
MailChimp Subscribe Form, Optin Builder, PopUp Builder, Form Builder
Affected Version
<= 4.0.9.3
CVSS
6.1Medium
Weakness type
CWE-601 · URL Redirection to Untrusted Site ('Open Redirect')
CVE
CVE-2023-32517
View all MailChimp Subscribe Form, Optin Builder, PopUp Builder, Form Builder vulnerabilities

At a glance

CVE-2023-32517 is a medium-severity URL Redirection to Untrusted Site ('Open Redirect') vulnerability in the MailChimp Subscribe Form, Optin Builder, PopUp Builder, Form Builder WordPress plugin, affecting versions <= 4.0.9.3. It carries a CVSS score of 6.1 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 4.0.9.4; sites on affected versions should update now. Disclosed May 2023, reported by minhtuanact.

Vulnerability Overview

The MailChimp Subscribe Forms plugin for WordPress is vulnerable to Open Redirect in versions up to, and including, 4.0.9.3. This is due to the application failing to properly verify a user-supplied input parameter. This makes it possible for unauthenticated attackers to exploit this issue and redirect users to arbitrary web sites and conduct phishing attacks; other attacks are also possible.

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.

CWE-601: URL Redirection to Untrusted Site ('Open Redirect')

Reaching this weakness in MailChimp Subscribe Form, Optin Builder, PopUp Builder, Form Builder <= 4.0.9.3 takes a caller who can reach the endpoint. An open redirect is a page that takes a destination from the request and sends the browser there without checking that the destination belongs to the site.

A link that starts on a trusted domain finishes on an attacker's, which is what makes phishing and consent-screen abuse credible to the person clicking it. For MailChimp Subscribe Form, Optin Builder, PopUp Builder, Form Builder the fix is 4.0.9.4: builds <= 4.0.9.3 are affected, anything from 4.0.9.4 onward is not.

Remediation

Update to version 4.0.9.4, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to MailChimp Subscribe Form, Optin Builder, PopUp Builder, Form Builder: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: MailChimp Subscribe Form, Optin Builder, PopUp Builder, Form Builder 4.0.9.4 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2023-32517https://www.wordfence.com/threat-intel/vulnerabilities/id/aba1ca3a-a937-400b-b175-2ca4e67a107dhttps://nvd.nist.gov/vuln/detail/CVE-2023-32517

Related records

Vulnerability data © Defiant, Inc., provided under the Wordfence Intelligence T&C