Description

If a hostname was blacklisted, it was possible to bypass the blacklist 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 IncludeSecurity/safeurl-python#6

Credit

https://github.com/Sim4n6

References

• GHSA-373w-rj84-pv6x
• IncludeSecurity/safeurl-python#6
• IncludeSecurity/safeurl-python@c4f9677