MailPoet Newsletters <= 2.7.2 - Reflected Cross-Site Scripting

2016-09-10 00:00
Sipke Mellema

Strategic Overview

Status
Patched in 2.7.3
Affected Plugin
MailPoet Newsletters (Previous)
Affected Version
<= 2.7.2
CVSS
6.5Medium
Weakness type
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE
CVE pending
View all MailPoet Newsletters (Previous) vulnerabilities

At a glance

This record tracks a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the MailPoet Newsletters (Previous) WordPress plugin, affecting versions <= 2.7.2. It carries a CVSS score of 6.5 (reachable over the network; low attack complexity). The issue is fixed in version 2.7.3; sites on affected versions should update now. Disclosed September 2016, reported by Sipke Mellema.

Vulnerability Overview

The MailPoet Newsletters plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the 'encodedForm' parameter in versions up to, and including, 2.7.2 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a link.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed.

CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

MailPoet Newsletters (Previous) <= 2.7.2 carries this weakness at encodedForm, and reaching it takes a caller who can reach the endpoint. Cross-site scripting happens when input from a request is written into a page without being escaped for the context it lands in, so the browser parses attacker-supplied text as markup or script.

Injected script runs with the privileges of whoever views the affected page, which is how these flaws turn into administrator session theft, silent account creation or persistent backdoors in page content. For MailPoet Newsletters (Previous) the fix is 2.7.3: builds <= 2.7.2 are affected, anything from 2.7.3 onward is not.

Remediation

Update to version 2.7.3, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to MailPoet Newsletters (Previous): WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: MailPoet Newsletters (Previous) 2.7.3 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Alerts

External References

https://www.wordfence.com/threat-intel/vulnerabilities/id/aff636ac-5bb5-4804-adf4-358ef3158d2d

Related records

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