{"id":"ALPINE-CVE-2021-29921","details":"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.","modified":"2026-08-27T22:18:01.602898713Z","published":"2021-05-06T13:15:12.573Z","upstream":["CVE-2021-29921"],"references":[{"type":"ADVISORY","url":"https://security.alpinelinux.org/vuln/CVE-2021-29921"}],"affected":[{"package":{"name":"python3","ecosystem":"Alpine:v3.15","purl":"pkg:apk/alpine/python3?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.9.5-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-29921.json"}},{"package":{"name":"python3","ecosystem":"Alpine:v3.16","purl":"pkg:apk/alpine/python3?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.9.5-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-29921.json"}},{"package":{"name":"python3","ecosystem":"Alpine:v3.17","purl":"pkg:apk/alpine/python3?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.9.5-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-29921.json"}},{"package":{"name":"python3","ecosystem":"Alpine:v3.18","purl":"pkg:apk/alpine/python3?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.9.5-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-29921.json"}},{"package":{"name":"python3","ecosystem":"Alpine:v3.19","purl":"pkg:apk/alpine/python3?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.9.5-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-29921.json"}},{"package":{"name":"python3","ecosystem":"Alpine:v3.20","purl":"pkg:apk/alpine/python3?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.9.5-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-29921.json"}},{"package":{"name":"python3","ecosystem":"Alpine:v3.21","purl":"pkg:apk/alpine/python3?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.9.5-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-29921.json"}},{"package":{"name":"python3","ecosystem":"Alpine:v3.22","purl":"pkg:apk/alpine/python3?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.9.5-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-29921.json"}},{"package":{"name":"python3","ecosystem":"Alpine:v3.23","purl":"pkg:apk/alpine/python3?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.9.5-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-29921.json"}},{"package":{"name":"python3","ecosystem":"Alpine:v3.24","purl":"pkg:apk/alpine/python3?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.9.5-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2021-29921.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"}]}