The Events Calendar < 4.1.1.1 - Open Redirect

2016-04-25 00:00
Paul Mynarsky

Strategic Overview

Status
Patched in 4.1.1.1
Affected Plugin
The Events Calendar
Affected Version
<= 4.1.1
CVSS
4.7Medium
Weakness type
CWE-601 · URL Redirection to Untrusted Site ('Open Redirect')
CVE
CVE pending
View all The Events Calendar vulnerabilities

At a glance

This record tracks a medium-severity URL Redirection to Untrusted Site ('Open Redirect') vulnerability in the The Events Calendar WordPress plugin, affecting versions <= 4.1.1. It carries a CVSS score of 4.7 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 4.1.1.1; sites on affected versions should update now. Disclosed April 2016, reported by Paul Mynarsky.

Vulnerability Overview

The Events Calendar plugin for WordPress is vulnerable to an open redirect vulnerability in versions before 4.1.1.1. This allows attackers to redirect victims to an untrusted site via a crafted link on a vulnerable trusted site.

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 The Events Calendar <= 4.1.1 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 The Events Calendar the fix is 4.1.1.1: builds <= 4.1.1 are affected, anything from 4.1.1.1 onward is not.

Remediation

Update to version 4.1.1.1, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to The Events Calendar: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: The Events Calendar 4.1.1.1 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Alerts

External References

https://www.wordfence.com/threat-intel/vulnerabilities/id/9bb026a4-02b1-4422-8c78-9983c49df43e

Related records

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