GHOSTSCRIPT FLAW LETS HACKERS HIJACK SERVERS VIA PDF UPLOADS

Summary from the TLDR InfoSec newsletter

Wordfence discovered a new vulnerability in the Ghostscript interpreter and rendering engine which could allow attackers to achieve remote code execution (RCE) using specially crafted PDFs. For WordPress sites to be vulnerable, an attacker must be able to upload PDFs which are then processed by a vulnerable version of Ghostscript to generate a preview or thumbnail. Other applications that use Ghostscript to generate previews or thumbnails from PDFs may also be vulnerable.