Nothing new, still broken, insecure by default since then: Python's e-mail libraries and certificate verification
Today, basically every e-mail provider supports TLS for their services and programmatically accessing e-mail services with Python code using TLS-wrapped clients is common. Python offers three libraries shipped with a standard installation for handling e-mail transfer. These modules are smtplib, imaplib, and poplib. While Python programming is usually straightforward, using these Python libraries require passing a magic parameter in the right way to use secure communication. If one has just read the summary on Stackoverflow, read a tutorial that does not mention security settings, or asked ChatGPT not specifically enough, it results in programs that do not defeat active attackers in a machine-in-the-middle (MITM) position. Our journey started, when we wrote an e-mail monitoring plugin in Python and ended for the time being with the notification of various open source projects.