A remote code execution (RCE) vulnerability via an insecure file upload exists in gugoan's Economizzer v.0.9-beta1 and commit 3730880 (April 2023). A malicious attacker can upload a PHP web shell as an attachment when adding a new cash book entry. Afterwards, the attacker may visit the web shell and execute arbitrary commands.
https://github.com/gugoan/economizzer
https://github.com/dub-flow/vulnerability-research/tree/main/CVE-2023-38874