CVE-2017-20206

Appointments <= 2.2.1 - Unauthenticated PHP Object Injection

Published Oct 18, 2025 CVSS 3.1 · 9.8 Critical EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Wpmudev
Wpmudev appointments
CPEs cpe:2.3:a:wpmudev:appointments:*:*:*:*:*:wordpress:*:*
Vendors & Products Wpmudev
Wpmudev appointments
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Wordpress
Wordpress wordpress
Vendors & Products Wordpress
Wordpress wordpress
Type Values Removed Values Added
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.
Title Appointments <= 2.2.1 - Unauthenticated PHP Object Injection
Weaknesses CWE-502
References
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
Wordfence
Published
Updated
Apr 8, 2026, 5:03 PM
Reserved
Oct 17, 2025, 3:00 PM
Status
Analyzed
Published
Oct 18, 2025, 4:15 AM
Modified
Jun 17, 2026, 1:15 AM