On the RIPSTech.com site they've posted a warning to the WordPress users out there about a vulnerability that would allow a malicious user to delete any file in the WordPress installation, not just file uploads.

At the time of writing no patch preventing this vulnerability is available. Any WordPress version, including the current 4.9.6 version, is susceptible to the vulnerability described in this blogpost.

For exploiting the vulnerability discussed in the following an attacker would need to gain the privileges to edit and delete media files beforehand. Thus, the vulnerability can be used to escalate privileges attained through the takeover of an account with a role as low as Author, or through the exploitation of another vulnerability/misconfiguration.

The post includes more details around the impact of the issue and where in the code the problem lies. It also offers a temporary "hotfix" as a way around the issue by adding a new filter that uses the basename function to reset the thumbnail data.