WordPress through 4.9.6 allows Author users to execute arbitrary code...

Vulnerability Description

WordPress through 4.9.6 allows Author users to execute arbitrary code by leveraging directory traversal in the wp-admin/post.php thumb parameter, which is passed to the PHP unlink function and can delete the wp-config.php file. This is related to missing filename validation in the wp-includes/post.php wp_delete_attachment function. The attacker must have capabilities for files and posts that are normally available only to the Author, Editor, and Administrator roles. The attack methodology is to delete wp-config.php and then launch a new installation process to increase the attacker's privileges.

References

• https://blog.ripstech.com/2018/wordpress-file-delete-to-code-execution/
• http://www.securityfocus.com/bid/104569
• https://www.debian.org/security/2018/dsa-4250
• https://wpvulndb.com/vulnerabilities/9100
• https://lists.debian.org/debian-lts-announce/2018/07/msg00046.html
• http://packetstormsecurity.com/files/164633/WordPress-4.9.6-Arbitrary-File-Deletion.html