Vulnerability record · CVE-2017-20206 · published 18 October 2025
CVE-2017-20206: Wpmudev appointments deserialization of untrusted data vulnerability
Wpmudev · Appointments
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.
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:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Affected products
1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.
References
| Link | Tags |
|---|---|
| https://plugins.trac.wordpress.org/changeset/1733186/appointments | Patch |
| https://www.wordfence.com/blog/2017/10/3-zero-day-plugin-vulnerabilities-exploited-wild/ | Press/Media CoverageThird Party Advisory |
| https://www.wordfence.com/threat-intel/vulnerabilities/id/7e8f230e-3f96-4efd-806d-72725b960303?source=cve | Third Party Advisory |
Track CVE-2017-20206 inside VULONE
Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.
Related vulnerabilities
Same products first, then exploited flaws of the same weakness class.
Source: NIST National Vulnerability Database (record CVE-2017-20206), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.
