Vulnerability · Published May 6, 2021 · Assigned by mitre

CVE-2021-29921

Critical 9.8

In plain English

A critical-severity security flaw in the python38-Cython package (AlmaLinux). There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 6.8% (higher than 94% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)9.8Critical
Exploit odds (30 days)6.8%top 6.0% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

In Python before 3,9,5, the ipaddress library mishandles leading zero characters in the octets of an IP address string. This (in some situations) allows attackers to bypass access control that is based on IP addresses.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
AlmaLinux:8python38-Cython0.29.14-4.module_el8.6.0+2778+cd494b30ALSA-2021:4162
AlmaLinux:8python38-PyMySQL0.10.1-1.module_el8.6.0+2778+cd494b30ALSA-2021:4162
AlmaLinux:8python38-asn1crypto1.2.0-3.module_el8.6.0+2778+cd494b30ALSA-2021:4162
AlmaLinux:8python38-atomicwrites1.3.0-8.module_el8.6.0+2778+cd494b30ALSA-2021:4162
AlmaLinux:8python38-attrs19.3.0-3.module_el8.6.0+2778+cd494b30ALSA-2021:4162
AlmaLinux:8python38-babel2.7.0-11.module_el8.6.0+2778+cd494b30ALSA-2021:4162
AlmaLinux:8python38-cffi1.13.2-3.module_el8.6.0+2778+cd494b30ALSA-2021:4162
AlmaLinux:8python38-chardet3.0.4-19.module_el8.6.0+2778+cd494b30ALSA-2021:4162
AlmaLinux:8python38-cryptography2.8-3.module_el8.6.0+2778+cd494b30ALSA-2021:4162
AlmaLinux:8python38-idna2.8-6.module_el8.6.0+2778+cd494b30ALSA-2021:4162
AlmaLinux:8python38-jinja22.10.3-5.module_el8.6.0+2778+cd494b30ALSA-2021:4162
AlmaLinux:8python38-markupsafe1.1.1-6.module_el8.6.0+2778+cd494b30ALSA-2021:4162
AlmaLinux:8python38-mod_wsgi4.6.8-3.module_el8.6.0+2778+cd494b30ALSA-2021:4162
AlmaLinux:8python38-more-itertools7.2.0-5.module_el8.6.0+2778+cd494b30ALSA-2021:4162
AlmaLinux:8python38-numpy1.17.3-6.module_el8.6.0+2778+cd494b30ALSA-2021:4162
AlmaLinux:8python38-numpy-doc1.17.3-6.module_el8.6.0+2778+cd494b30ALSA-2021:4162
AlmaLinux:8python38-numpy-f2py1.17.3-6.module_el8.6.0+2778+cd494b30ALSA-2021:4162
AlmaLinux:8python38-packaging19.2-3.module_el8.6.0+2778+cd494b30ALSA-2021:4162
AlmaLinux:8python38-pluggy0.13.0-3.module_el8.6.0+2778+cd494b30ALSA-2021:4162
AlmaLinux:8python38-ply3.11-10.module_el8.6.0+2778+cd494b30ALSA-2021:4162
AlmaLinux:8python38-psutil5.6.4-4.module_el8.6.0+2778+cd494b30ALSA-2021:4162
AlmaLinux:8python38-psycopg22.8.4-4.module_el8.6.0+2778+cd494b30ALSA-2021:4162
AlmaLinux:8python38-psycopg2-doc2.8.4-4.module_el8.6.0+2778+cd494b30ALSA-2021:4162
AlmaLinux:8python38-psycopg2-tests2.8.4-4.module_el8.6.0+2778+cd494b30ALSA-2021:4162
AlmaLinux:8python38-py1.8.0-8.module_el8.6.0+2778+cd494b30ALSA-2021:4162
AlmaLinux:8python38-pycparser2.19-3.module_el8.6.0+2778+cd494b30ALSA-2021:4162
AlmaLinux:8python38-pyparsing2.4.5-3.module_el8.6.0+2778+cd494b30ALSA-2021:4162
AlmaLinux:8python38-pysocks1.7.1-4.module_el8.6.0+2778+cd494b30ALSA-2021:4162
AlmaLinux:8python38-pytest4.6.6-3.module_el8.6.0+2778+cd494b30ALSA-2021:4162
AlmaLinux:8python38-pytz2019.3-3.module_el8.6.0+2778+cd494b30ALSA-2021:4162
AlmaLinux:8python38-pyyaml5.4.1-1.module_el8.6.0+2778+cd494b30ALSA-2021:4162
AlmaLinux:8python38-requests2.22.0-9.module_el8.6.0+2778+cd494b30ALSA-2021:4162
AlmaLinux:8python38-scipy1.3.1-4.module_el8.6.0+2778+cd494b30ALSA-2021:4162
AlmaLinux:8python38-setuptools41.6.0-5.module_el8.6.0+2778+cd494b30ALSA-2021:4162
AlmaLinux:8python38-setuptools-wheel41.6.0-5.module_el8.6.0+2778+cd494b30ALSA-2021:4162
AlmaLinux:8python38-six1.12.0-10.module_el8.6.0+2778+cd494b30ALSA-2021:4162
AlmaLinux:8python38-urllib31.25.7-5.module_el8.6.0+2778+cd494b30ALSA-2021:4162
AlmaLinux:8python38-wcwidth0.1.7-16.module_el8.6.0+2778+cd494b30ALSA-2021:4162
AlmaLinux:8python38-wheel0.33.6-6.module_el8.6.0+2778+cd494b30ALSA-2021:4162
AlmaLinux:8python38-wheel-wheel0.33.6-6.module_el8.6.0+2778+cd494b30ALSA-2021:4162
AlmaLinux:8python39-Cython0.29.21-5.module_el8.6.0+2780+a40f65e1ALSA-2021:4160
AlmaLinux:8python39-PyMySQL0.10.1-2.module_el8.6.0+2780+a40f65e1ALSA-2021:4160
AlmaLinux:8python39-attrs20.3.0-2.module_el8.6.0+2780+a40f65e1ALSA-2021:4160
AlmaLinux:8python39-cffi1.14.3-2.module_el8.6.0+2780+a40f65e1ALSA-2021:4160
AlmaLinux:8python39-chardet3.0.4-19.module_el8.6.0+2780+a40f65e1ALSA-2021:4160
AlmaLinux:8python39-cryptography3.3.1-2.module_el8.6.0+2780+a40f65e1ALSA-2021:4160
AlmaLinux:8python39-idna2.10-3.module_el8.6.0+2780+a40f65e1ALSA-2021:4160
AlmaLinux:8python39-iniconfig1.1.1-2.module_el8.6.0+2780+a40f65e1ALSA-2021:4160
AlmaLinux:8python39-mod_wsgi4.7.1-4.module_el8.6.0+2780+a40f65e1ALSA-2021:4160
AlmaLinux:8python39-more-itertools8.5.0-2.module_el8.6.0+2780+a40f65e1ALSA-2021:4160
AlmaLinux:8python39-numpy1.19.4-3.module_el8.6.0+2780+a40f65e1ALSA-2021:4160
AlmaLinux:8python39-numpy-doc1.19.4-3.module_el8.6.0+2780+a40f65e1ALSA-2021:4160
AlmaLinux:8python39-numpy-f2py1.19.4-3.module_el8.6.0+2780+a40f65e1ALSA-2021:4160
AlmaLinux:8python39-packaging20.4-4.module_el8.6.0+2780+a40f65e1ALSA-2021:4160
AlmaLinux:8python39-pluggy0.13.1-3.module_el8.6.0+2780+a40f65e1ALSA-2021:4160
AlmaLinux:8python39-ply3.11-10.module_el8.6.0+2780+a40f65e1ALSA-2021:4160
AlmaLinux:8python39-psutil5.8.0-4.module_el8.6.0+2780+a40f65e1ALSA-2021:4160
AlmaLinux:8python39-psycopg22.8.6-2.module_el8.6.0+2780+a40f65e1ALSA-2021:4160
AlmaLinux:8python39-psycopg2-doc2.8.6-2.module_el8.6.0+2780+a40f65e1ALSA-2021:4160
AlmaLinux:8python39-psycopg2-tests2.8.6-2.module_el8.6.0+2780+a40f65e1ALSA-2021:4160
AlmaLinux:8python39-py1.10.0-1.module_el8.6.0+2780+a40f65e1ALSA-2021:4160
AlmaLinux:8python39-pycparser2.20-3.module_el8.6.0+2780+a40f65e1ALSA-2021:4160
AlmaLinux:8python39-pyparsing2.4.7-5.module_el8.6.0+2780+a40f65e1ALSA-2021:4160
AlmaLinux:8python39-pysocks1.7.1-4.module_el8.6.0+2780+a40f65e1ALSA-2021:4160
AlmaLinux:8python39-pytest6.0.2-2.module_el8.6.0+2780+a40f65e1ALSA-2021:4160
AlmaLinux:8python39-pyyaml5.4.1-1.module_el8.6.0+2780+a40f65e1ALSA-2021:4160
AlmaLinux:8python39-requests2.25.0-2.module_el8.6.0+2780+a40f65e1ALSA-2021:4160
AlmaLinux:8python39-scipy1.5.4-3.module_el8.6.0+2780+a40f65e1ALSA-2021:4160
AlmaLinux:8python39-setuptools50.3.2-4.module_el8.6.0+2780+a40f65e1ALSA-2021:4160
AlmaLinux:8python39-setuptools-wheel50.3.2-4.module_el8.6.0+2780+a40f65e1ALSA-2021:4160
AlmaLinux:8python39-six1.15.0-3.module_el8.6.0+2780+a40f65e1ALSA-2021:4160
AlmaLinux:8python39-toml0.10.1-5.module_el8.6.0+2780+a40f65e1ALSA-2021:4160
AlmaLinux:8python39-urllib31.25.10-4.module_el8.6.0+2780+a40f65e1ALSA-2021:4160
AlmaLinux:8python39-wcwidth0.2.5-3.module_el8.6.0+2780+a40f65e1ALSA-2021:4160
AlmaLinux:8python39-wheel1:0.35.1-4.module_el8.6.0+2780+a40f65e1ALSA-2021:4160
AlmaLinux:8python39-wheel-wheel1:0.35.1-4.module_el8.6.0+2780+a40f65e1ALSA-2021:4160
Alpine:v3.20python33.9.5-r0ALPINE-CVE-2021-29921
Alpine:v3.21python33.9.5-r0ALPINE-CVE-2021-29921
Alpine:v3.22python33.9.5-r0ALPINE-CVE-2021-29921
Alpine:v3.23python33.9.5-r0ALPINE-CVE-2021-29921
Alpine:v3.24python33.9.5-r0ALPINE-CVE-2021-29921
Debian:12pypy37.3.8+dfsg-1DEBIAN-CVE-2021-29921
Debian:13pypy37.3.8+dfsg-1DEBIAN-CVE-2021-29921
Debian:14pypy37.3.8+dfsg-1DEBIAN-CVE-2021-29921
Rocky Linux:8Cython0:0.29.21-5.module+el8.4.0+574+843c4898RLSA-2021:4160
Rocky Linux:8Cython0:0.29.14-4.module+el8.4.0+570+c2eaf144RLSA-2021:4162
Rocky Linux:8PyYAML0:5.4.1-1.module+el8.5.0+672+ab6eb015RLSA-2021:4160
Rocky Linux:8PyYAML0:5.4.1-1.module+el8.4.0+574+843c4898RLSA-2021:4162
Rocky Linux:8PyYAML0:5.4.1-1.module+el8.5.0+672+ab6eb015RLSA-2021:4162
Rocky Linux:8PyYAML0:5.4.1-1.module+el8.4.0+574+843c4898RLSA-2021:4160
Rocky Linux:8babel0:2.7.0-11.module+el8.5.0+672+ab6eb015RLSA-2021:4162
Rocky Linux:8mod_wsgi0:4.7.1-4.module+el8.4.0+574+843c4898RLSA-2021:4160
Rocky Linux:8mod_wsgi0:4.6.8-3.module+el8.4.0+570+c2eaf144RLSA-2021:4162
Rocky Linux:8numpy0:1.17.3-6.module+el8.5.0+672+ab6eb015RLSA-2021:4162
Rocky Linux:8numpy0:1.19.4-3.module+el8.5.0+673+10283621RLSA-2021:4160
Rocky Linux:8pybind110:2.6.1-2.module+el8.4.0+574+843c4898RLSA-2021:4160
Rocky Linux:8pytest0:6.0.2-2.module+el8.4.0+574+843c4898RLSA-2021:4160
Rocky Linux:8pytest0:4.6.6-3.module+el8.4.0+570+c2eaf144RLSA-2021:4162
Rocky Linux:8python-PyMySQL0:0.10.1-2.module+el8.4.0+597+ddf0ddeaRLSA-2021:4160
Rocky Linux:8python-PyMySQL0:0.10.1-2.module+el8.4.0+574+843c4898RLSA-2021:4160
Rocky Linux:8python-PyMySQL0:0.10.1-1.module+el8.5.0+672+ab6eb015RLSA-2021:4162
Rocky Linux:8python-PyMySQL0:0.10.1-1.module+el8.4.0+570+c2eaf144RLSA-2021:4162
Rocky Linux:8python-asn1crypto0:1.2.0-3.module+el8.4.0+570+c2eaf144RLSA-2021:4162
Rocky Linux:8python-atomicwrites0:1.3.0-8.module+el8.4.0+570+c2eaf144RLSA-2021:4162
Rocky Linux:8python-attrs0:20.3.0-2.module+el8.4.0+574+843c4898RLSA-2021:4160
Rocky Linux:8python-attrs0:19.3.0-3.module+el8.4.0+570+c2eaf144RLSA-2021:4162
Rocky Linux:8python-cffi0:1.14.3-2.module+el8.4.0+574+843c4898RLSA-2021:4160
Rocky Linux:8python-cffi0:1.13.2-3.module+el8.4.0+570+c2eaf144RLSA-2021:4162
Rocky Linux:8python-chardet0:3.0.4-19.module+el8.4.0+570+c2eaf144RLSA-2021:4162
Rocky Linux:8python-chardet0:3.0.4-19.module+el8.4.0+570+c2eaf144RLSA-2021:4160
Rocky Linux:8python-cryptography0:3.3.1-2.module+el8.5.0+673+10283621RLSA-2021:4160
Rocky Linux:8python-cryptography0:2.8-3.module+el8.4.0+570+c2eaf144RLSA-2021:4162
Rocky Linux:8python-cryptography0:2.8-3.module+el8.5.0+672+ab6eb015RLSA-2021:4162
Rocky Linux:8python-cryptography0:3.3.1-2.module+el8.4.0+574+843c4898RLSA-2021:4160
Rocky Linux:8python-idna0:2.8-6.module+el8.4.0+570+c2eaf144RLSA-2021:4162
Rocky Linux:8python-idna0:2.10-3.module+el8.4.0+574+843c4898RLSA-2021:4160
Rocky Linux:8python-iniconfig0:1.1.1-2.module+el8.4.0+574+843c4898RLSA-2021:4160
Rocky Linux:8python-jinja20:2.10.3-5.module+el8.5.0+672+ab6eb015RLSA-2021:4162
Rocky Linux:8python-lxml0:4.4.1-6.module+el8.5.0+672+ab6eb015RLSA-2021:4162
Rocky Linux:8python-lxml0:4.6.2-3.module+el8.5.0+673+10283621RLSA-2021:4160
Rocky Linux:8python-markupsafe0:1.1.1-6.module+el8.4.0+570+c2eaf144RLSA-2021:4162
Rocky Linux:8python-more-itertools0:8.5.0-2.module+el8.4.0+574+843c4898RLSA-2021:4160
Rocky Linux:8python-more-itertools0:7.2.0-5.module+el8.4.0+570+c2eaf144RLSA-2021:4162
Rocky Linux:8python-packaging0:20.4-4.module+el8.4.0+574+843c4898RLSA-2021:4160
Rocky Linux:8python-packaging0:19.2-3.module+el8.4.0+570+c2eaf144RLSA-2021:4162
Rocky Linux:8python-pluggy0:0.13.1-3.module+el8.4.0+574+843c4898RLSA-2021:4160
Rocky Linux:8python-pluggy0:0.13.0-3.module+el8.4.0+570+c2eaf144RLSA-2021:4162
Rocky Linux:8python-ply0:3.11-10.module+el8.4.0+570+c2eaf144RLSA-2021:4162
Rocky Linux:8python-ply0:3.11-10.module+el8.4.0+570+c2eaf144RLSA-2021:4160
Rocky Linux:8python-psutil0:5.8.0-4.module+el8.4.0+574+843c4898RLSA-2021:4160
Rocky Linux:8python-psutil0:5.8.0-4.module+el8.5.0+673+10283621RLSA-2021:4160
Rocky Linux:8python-psutil0:5.6.4-4.module+el8.5.0+672+ab6eb015RLSA-2021:4162
Rocky Linux:8python-psycopg20:2.8.6-2.module+el8.5.0+673+10283621RLSA-2021:4160
Rocky Linux:8python-psycopg20:2.8.4-4.module+el8.6.0+794+eba84017RLSA-2021:4162
Rocky Linux:8python-psycopg20:2.8.4-4.module+el8.4.0+570+c2eaf144RLSA-2021:4162
Rocky Linux:8python-psycopg20:2.8.6-2.module+el8.6.0+795+de4edbccRLSA-2021:4160
Rocky Linux:8python-psycopg20:2.8.6-2.module+el8.4.0+574+843c4898RLSA-2021:4160
Rocky Linux:8python-py0:1.8.0-8.module+el8.4.0+570+c2eaf144RLSA-2021:4162
Rocky Linux:8python-py0:1.10.0-1.module+el8.4.0+574+843c4898RLSA-2021:4160
Rocky Linux:8python-pycparser0:2.20-3.module+el8.4.0+574+843c4898RLSA-2021:4160
Rocky Linux:8python-pycparser0:2.19-3.module+el8.4.0+570+c2eaf144RLSA-2021:4162
Rocky Linux:8python-pysocks0:1.7.1-4.module+el8.4.0+570+c2eaf144RLSA-2021:4162
Rocky Linux:8python-pysocks0:1.7.1-4.module+el8.4.0+570+c2eaf144RLSA-2021:4160
Rocky Linux:8python-requests0:2.22.0-9.module+el8.4.0+570+c2eaf144RLSA-2021:4162
Rocky Linux:8python-requests0:2.25.0-2.module+el8.4.0+574+843c4898RLSA-2021:4160
Rocky Linux:8python-toml0:0.10.1-5.module+el8.4.0+574+843c4898RLSA-2021:4160
Rocky Linux:8python-urllib30:1.25.7-5.module+el8.5.0+672+ab6eb015RLSA-2021:4162
Rocky Linux:8python-urllib30:1.25.10-4.module+el8.5.0+673+10283621RLSA-2021:4160
Rocky Linux:8python-wcwidth0:0.1.7-16.module+el8.4.0+570+c2eaf144RLSA-2021:4162
Rocky Linux:8python-wcwidth0:0.2.5-3.module+el8.4.0+574+843c4898RLSA-2021:4160
Rocky Linux:8python-wheel0:0.33.6-6.module+el8.5.0+672+ab6eb015RLSA-2021:4162
Rocky Linux:8python-wheel1:0.35.1-4.module+el8.5.0+673+10283621RLSA-2021:4160
Rocky Linux:8python380:3.8.8-4.module+el8.5.0+672+ab6eb015RLSA-2021:4162
Rocky Linux:8python390:3.9.6-2.module+el8.5.0+673+10283621RLSA-2021:4160
Rocky Linux:8python3x-pip0:20.2.4-6.module+el8.5.0+673+10283621RLSA-2021:4160
Rocky Linux:8python3x-pip0:19.3.1-4.module+el8.5.0+672+ab6eb015RLSA-2021:4162
Rocky Linux:8python3x-pyparsing0:2.4.5-3.module+el8.4.0+570+c2eaf144RLSA-2021:4162
Rocky Linux:8python3x-pyparsing0:2.4.7-5.module+el8.4.0+574+843c4898RLSA-2021:4160
Rocky Linux:8python3x-setuptools0:50.3.2-4.module+el8.5.0+673+10283621RLSA-2021:4160
Rocky Linux:8python3x-setuptools0:41.6.0-5.module+el8.5.0+672+ab6eb015RLSA-2021:4162
Rocky Linux:8python3x-six0:1.15.0-3.module+el8.4.0+574+843c4898RLSA-2021:4160
Rocky Linux:8python3x-six0:1.12.0-10.module+el8.4.0+570+c2eaf144RLSA-2021:4162
Rocky Linux:8pytz0:2019.3-3.module+el8.4.0+570+c2eaf144RLSA-2021:4162
Rocky Linux:8scipy0:1.5.4-3.module+el8.4.0+574+843c4898RLSA-2021:4160
Rocky Linux:8scipy0:1.5.4-3.module+el8.5.0+673+10283621RLSA-2021:4160
Rocky Linux:8scipy0:1.3.1-4.module+el8.4.0+570+c2eaf144RLSA-2021:4162
Rocky Linux:8scipy0:1.3.1-4.module+el8.5.0+672+ab6eb015RLSA-2021:4162
Ubuntu:22.04:LTSpython3.103.10.12-1~22.04.4USN-6891-1

Affected products (as reported)

VendorProductVersions
n/a n/a n/a

References