BaseFortify

Publication date: 2025-10-18

Last updated on: 2025-12-23

Assigner: Wordfence

Description

The Appointments plugin for WordPress is vulnerable to PHP Object Injection in versions up to, and including, 2.2.1 via deserialization of untrusted input from the `wpmudev_appointments` cookie. This allows unauthenticated attackers to inject a PHP Object. Attackers were actively exploiting this vulnerability with the WP_Theme() class to create backdoors.

CVSS Scores

EPSS Scores

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Meta Information

Published

2025-10-18

Last Modified

2025-12-23

Generated

2026-07-06

AI Q&A

2025-10-18

EPSS Evaluated

2026-07-04

NVD

CVE-2017-20206

Affected Vendors & Products

Vendor	Product	Version / Range
wpmudev	appointments	to 2.2.1 (inc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-502	The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.

Attack-Flow Graph

Executive Summary

This vulnerability exists in the Appointments plugin for WordPress versions up to 2.2.1. It is a PHP Object Injection flaw caused by deserialization of untrusted input from the 'wpmudev_appointments' cookie. This allows unauthenticated attackers to inject malicious PHP objects, which can be exploited to create backdoors using the WP_Theme() class.

Impact Analysis

The vulnerability can have severe impacts including unauthorized remote code execution, allowing attackers to create backdoors on the affected system. This can lead to full compromise of the WordPress site, data theft, site defacement, or further attacks on the hosting environment.

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