CVE-2017-20206
published 2025-10-18CVE-2017-20206: 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…
PriorityP183critical9.8CVSS 3.1
AVNACLPRNUINSUCHIHAH
ITWVulnCheck KEV
Exploited in the wild
EPSS
0.67%
47.3th percentile
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.
Affected
2 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| wpmudev | appointments | < 2.2.2 | 2.2.2 |
| wpmudev | appointments | <= 2.2.1 | — |
CVSS provenance
nvdv3.19.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
vulncheck9.8CRITICAL
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GHSA
GHSA-7mpm-gf56-q8wv: The Appointments plugin for WordPress is vulnerable to PHP Object Injection in versions up to, and including, 2
ghsa_unreviewed·2025-10-18
CVE-2017-20206 [CRITICAL] CWE-502 GHSA-7mpm-gf56-q8wv: The Appointments plugin for WordPress is vulnerable to PHP Object Injection in versions up to, and including, 2
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.
VulnCheck
wpmudev appointments Deserialization of Untrusted Data
vulncheck·2017·CVSS 9.8
CVE-2017-20206 [CRITICAL] wpmudev appointments Deserialization of Untrusted Data
wpmudev appointments Deserialization of Untrusted Data
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.
Affected: WPMU Dev Appointments Plugin for WordPress
Required Action: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.
Exploitation References: https://www.wordfence.com/blog/2017/10/3-zero-day-plugin-vulnerabilities-exploited-wild/; https://www.cve.org/cverecord?id=CVE-2017-20206
No detection rules found.
No public exploits indexed.
No writeups or analysis indexed.
2025-10-18
Published
Exploited in the wild