Description
The WordPress plugin "MailPoet Newsletters" (wysija-newsletters) before version 2.6.8 is vulnerable to an unauthenticated file upload. An attacker can use the Upload Theme functionality to upload a zip file containing a PHP shell.
Remediation
Upgrade to the latest version of MailPoet Newsletters (this issue was fixed in version 2.6.8).
References
MailPoet Newsletters Changelog
Remote File Upload Vulnerability in WordPress MailPoet Plugin (wysija-newsletters)
WordPress MailPoet Newsletters (wysija-newsletters) Unauthenticated File Upload
Related Vulnerabilities
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Deserialization of Untrusted Data (.NET BinaryFormatter Object Deserialization)
WordPress Plugin SupportCandy Arbitrary File Upload (2.0.0)
WordPress Plugin Hungred Post Thumbnail 'hpt_file_upload.php' Arbitrary File Upload (2.1.9)
WordPress Plugin Templatic Tevolution Arbitrary File Upload (2.3.6)