Security Considerations

The following modules have specific security considerations:

• base64: base64 security considerations in RFC 4648

• ftplib: default TLS context does not verify server certificates; pass a context from ssl.create_default_context() to verify them

• hashlib: all constructors take a “usedforsecurity” keyword-only argument disabling known insecure and blocked algorithms

• http.server is not suitable for production use, only implementing basic security checks. See the security considerations.

• imaplib: default TLS context does not verify server certificates; pass a context from ssl.create_default_context() to verify them

• logging: Logging configuration uses eval()

• multiprocessing: Connection.recv() uses pickle

• pickle: Restricting globals in pickle

• poplib: default TLS context does not verify server certificates; pass a context from ssl.create_default_context() to verify them

• random shouldn’t be used for security purposes, use secrets instead

• shelve: shelve is based on pickle and thus unsuitable for dealing with untrusted sources

• smtplib: default TLS context does not verify server certificates; pass a context from ssl.create_default_context() to verify them

• ssl: SSL/TLS security considerations

• subprocess: Subprocess security considerations

• tempfile: mktemp is deprecated due to vulnerability to race conditions

• xml: XML security

• zipfile: maliciously prepared .zip files can cause disk volume exhaustion

The -I command line option can be used to run Python in isolated mode. When it cannot be used, the -P option or the PYTHONSAFEPATH environment variable can be used to not prepend a potentially unsafe path to sys.path such as the current directory, the script’s directory or an empty string.