CVE-2017-20206

9.8 CRITICAL
Published: October 18, 2025 Modified: December 23, 2025
View on NVD

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.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://plugins.trac.wordpress.org/changeset/1733186/appointments
Source: security@wordfence.com
Patch
https://www.wordfence.com/blog/2017/10/3-zero-day-plugin-vulnerabilities-exploited-wild/
Source: security@wordfence.com
Press/Media Coverage Third Party Advisory
https://www.wordfence.com/threat-intel/vulnerabilities/id/7e8f230e-3f96-4efd-806d-72725b960303?source=cve
Source: security@wordfence.com
Third Party Advisory

3 reference(s) from NVD

Quick Stats

CVSS v3 Score
9.8 / 10.0
EPSS (Exploit Probability)
0.2%
43th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

CWE-502

Affected Vendors

wpmudev

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