The “ipaddress” module contained incorrect information about whether certain IPv4 and IPv6 addresses were designated as “globally reachable” or “private”. This affected the is_private and is_global properties of the ipaddress.IPv4Address, ipaddress.IPv4Network, ipaddress.IPv6Address, and ipaddress.IPv6Network classes, where values wouldn’t be returned in accordance with the latest information from the IANA Special-Purpose Address Registries.

CPython 3.12.4 and 3.13.0a6 contain updated information from these registries and thus have the intended behavior.

References

• https://nvd.nist.gov/vuln/detail/CVE-2024-4032
• python/cpython#113171
• python/cpython#113179
• https://mail.python.org/archives/list/security-announce@python.org/thread/NRUHDUS2IV2USIZM2CVMSFL6SCKU3RZA
• https://www.iana.org/assignments/iana-ipv4-special-registry/iana-ipv4-special-registry.xhtml
• https://www.iana.org/assignments/iana-ipv6-special-registry/iana-ipv6-special-registry.xhtml
• python/cpython@22adf29
• python/cpython@40d75c2
• python/cpython@895f7e2
• python/cpython@ba43157
• python/cpython@c62c9e5
• python/cpython@f86b17a
• http://www.openwall.com/lists/oss-security/2024/06/17/3