CVE-2020-14422

Lib/ipaddress.py in Python through 3.8.3 improperly computes hash values in the IPv4Interface and IPv6Interface classes, which might allow a remote attacker to cause a denial of service if an application is affected by the performance of a dictionary containing IPv4Interface or IPv6Interface objects, and this attacker can cause many dictionary entries to be created. This is fixed in: v3.5.10, v3.5.10rc1; v3.6.12; v3.7.9; v3.8.4, v3.8.4rc1, v3.8.5, v3.8.6, v3.8.6rc1; v3.9.0, v3.9.0b4, v3.9.0b5, v3.9.0rc1, v3.9.0rc2.

Weakness

The product uses insufficiently random numbers or values in a security context that depends on unpredictable numbers.

Affected Software

Potential Mitigations

• Use a well-vetted algorithm that is currently considered to be strong by experts in the field, and select well-tested implementations with adequate length seeds.
• In general, if a pseudo-random number generator is not advertised as being cryptographically secure, then it is probably a statistical PRNG and should not be used in security-sensitive contexts.
• Pseudo-random number generators can produce predictable numbers if the generator is known and the seed can be guessed. A 256-bit seed is a good starting point for producing a “random enough” number.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/112.html
• https://cwe.mitre.org/data/definitions/485.html
• https://cwe.mitre.org/data/definitions/59.html

References

• http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00003.html
• http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00006.html
• http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00032.html
• http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00041.html
• https://bugs.python.org/issue41004
• https://github.com/python/cpython/pull/20956
• https://lists.debian.org/debian-lts-announce/2020/07/msg00011.html
• https://lists.debian.org/debian-lts-announce/2023/05/msg00016.html
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/36XI3EEQNMHGOZEI63Y7UV6XZRELYEAU/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/CNHPQGSP2YM3JAUD2VAMPXTIUQTZ2M2U/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/CTUNTBJ3POHONQOTLEZC46POCIYYTAKZ/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FCCZTAYZATTNSNEAXWA7U3HCO2OVQKT5/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LE4O3PNDNNOMSKHNUKZKD3NGHIFUFDPX/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NTBKKOLFFNHG6CM4ACDX4APHSD5ZX5N4/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OXI72HIHMXCQFWTULUXDG7VDA2BCYL4Y/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/V3TALOUBYU2MQD4BPLRTDQUMBKGCAXUA/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/V53P2YOLEQH4J7S5QHXMKMZYFTVVMTMO/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VT4AF72TJ2XNIKCR4WEBR7URBJJ4YZRD/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/X36Y523UAZY5QFXZAAORNFY63HLBWX7N/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YILCHHTNLH4GG4GSQBX2MZRKZBXOLCKE/
• https://security.gentoo.org/glsa/202008-01
• https://security.netapp.com/advisory/ntap-20200724-0004/
• https://usn.ubuntu.com/4428-1/
• https://www.oracle.com/security-alerts/cpujan2021.html