GMS-2023-1894: SafeURL-Python's hostname blocklist does not block FQDNs

Description

If a hostname was block listed, it was possible to bypass the block list by requesting the FQDN of the host (e.g. adding . to the end).

Impact

The main purpose of this library is to block requests to internal/private IPs and these cannot be bypassed using this finding. But if a library user had specifically set certain hostnames as blocked, then an attacker would be able to circumvent that block to cause SSRFs to request those hostnames.

Patches

Fixed by https://github.com/IncludeSecurity/safeurl-python/pull/6

Credit

https://github.com/Sim4n6