CVE-2017-20207

The Flickr Gallery plugin for WordPress is vulnerable to PHP Object Injection in versions up to, and including, 1.5.2 via deserialization of untrusted input from the `pager ` parameter. This allows unauthenticated attackers to inject a PHP Object. Attackers were actively exploiting this vulnerability with the WP_Theme() class to create backdoors.

Score

CVSS 3.1 9.8 Critical

Status

Analyzed - security@wordfence.com

Published

2025-10-18

Last modified

2026-04-08

Weaknesses

CWE-502

Affected products

• Flickr Gallery (Dan Coulter)
• Flickr Gallery (Dancoulter)

References

• https://plugins.trac.wordpress.org/changeset/1737576/flickr-gallery
• https://www.wordfence.com/blog/2017/10/3-zero-day-plugin-vulnerabilities-exploited-wild/
• https://www.wordfence.com/threat-intel/vulnerabilities/id/b52ae51d-7b9a-4047-82bf-723ea87d2375?source=cve