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.
Upstream:released (4.9.7+dfsg1-1)
Ubuntu 12.04 ESM (Precise Pangolin):DNE
Ubuntu 14.04 ESM (Trusty Tahr):DNE (trusty was needs-triage)
Ubuntu 16.04 LTS (Xenial Xerus):needed
Ubuntu 18.04 LTS (Bionic Beaver):needed
Ubuntu 19.10 (Eoan Ermine):not-affected (4.9.7+dfsg1-1)
Ubuntu 20.04 (Focal Fossa):not-affected (4.9.7+dfsg1-1)
More Information

Updated: 2020-01-29 18:51:55 UTC (commit 40f18bf14da5fb50662e1f861ea594a462b207fe)