The SecureDrop Client is a desktop application for journalists to communicate with sources and work with submissions on the SecureDrop Workstation. Prior to version 0.14.1, a malicious SecureDrop Server could obtain code execution on the SecureDrop Client virtual machine (`sd-app`). SecureDrop Server itself has multiple layers of built-in hardening, and is a dedicated physical machine exposed on the internet only via Tor hidden services for the Source and Journalist interfaces, and optionally via remote SSH access over another Tor hidden service. A newsroom's SecureDrop Workstation communicates only with its own dedicated SecureDrop Server. The SecureDrop Client runs in a dedicated Qubes virtual machine, named `sd-app`, as part of the SecureDrop Workstation. The private OpenPGP key used to decrypt submissions and replies is stored in a separate virtual machine and never accessed directly. The vulnerability lies in the code responsible for downloading replies. The filename of the repl…