CVE-2017-20206 | The Appointments plugin for WordPress is vulnerable to PHP O… | CVSS 9.8 CRITICAL

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.

Metadata

CVE ID: CVE-2017-20206
State: PUBLISHED
Assigner: Wordfence
Reserved: 2025-10-17 15:00 UTC
Published: 2025-10-18 03:33 UTC
Last updated: 2026-04-08 17:03 UTC
Primary CWE: CWE-502
CWE-502 Deserialization of Untrusted Data
Vendor / Product: wpmudev / Appointments
Sources: cve.org · NVD

Severity & Metrics

9.8 CRITICAL CVSS 3.1

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

SSVC — CISA Coordinator

Exploitation: none
Automatable: yes
Tech. Impact: total

Affected products (1)

Vendor	Product	Platform	Versions
wpmudev	Appointments	—	0 < 2.2.2

Weakness (CWE)

CWE	Source	Description
CWE-502	cna	CWE-502 Deserialization of Untrusted Data

CVSS scores (1)

Score	Severity	Version	Source	Vector
9.8	CRITICAL	3.1	cna	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References (3)