{"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":"2025-12-03T22:48:35.717576Z","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"}]}],"versions":["3.1.3-r0","3.2.0-r0","3.2.3-r0","3.3.0-r0","3.3.2-r0","3.3.3-r0","3.3.4-r0","3.4.1-r0","3.4.2-r0","3.4.2-r1","3.4.3-r1","3.4.3-r2","3.5.0-r0","3.5.1-r0","3.5.1-r1","3.5.1-r2","3.5.1-r3","3.5.2-r0","3.5.2-r1","3.5.2-r10","3.5.2-r2","3.5.2-r3","3.5.2-r4","3.5.2-r5","3.5.2-r6","3.5.2-r7","3.5.2-r8","3.5.2-r9","3.6.0-r0","3.6.1-r0","3.6.1-r1","3.6.1-r2","3.6.1-r3","3.6.1-r4","3.6.2-r0","3.6.2-r1","3.6.2-r2","3.6.2-r3","3.6.3-r3","3.6.3-r4","3.6.3-r5","3.6.3-r6","3.6.3-r7","3.6.3-r8","3.6.3-r9","3.6.4-r0","3.6.4-r1","3.6.6-r0","3.6.6-r1","3.6.6-r2","3.6.6-r3","3.6.7-r0","3.6.8-r0","3.6.8-r1","3.6.8-r2","3.7.2-r0","3.7.3-r0","3.7.3-r1","3.7.4-r0","3.7.5-r0","3.7.5-r1","3.8.0-r0","3.8.1-r0","3.8.1-r1","3.8.1-r2","3.8.1-r3","3.8.2-r0","3.8.2-r1","3.8.2-r2","3.8.2-r3","3.8.2-r4","3.8.2-r5","3.8.2-r6","3.8.2-r7","3.8.3-r0","3.8.4-r0","3.8.5-r0","3.8.5-r1","3.8.5-r2","3.8.6-r0","3.8.7-r0","3.8.7-r1","3.8.7-r2","3.8.7-r3","3.8.8-r0","3.9.1-r0","3.9.2-r0","3.9.4-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"}]}],"versions":["3.1.3-r0","3.2.0-r0","3.2.3-r0","3.3.0-r0","3.3.2-r0","3.3.3-r0","3.3.4-r0","3.4.1-r0","3.4.2-r0","3.4.2-r1","3.4.3-r1","3.4.3-r2","3.5.0-r0","3.5.1-r0","3.5.1-r1","3.5.1-r2","3.5.1-r3","3.5.2-r0","3.5.2-r1","3.5.2-r10","3.5.2-r2","3.5.2-r3","3.5.2-r4","3.5.2-r5","3.5.2-r6","3.5.2-r7","3.5.2-r8","3.5.2-r9","3.6.0-r0","3.6.1-r0","3.6.1-r1","3.6.1-r2","3.6.1-r3","3.6.1-r4","3.6.2-r0","3.6.2-r1","3.6.2-r2","3.6.2-r3","3.6.3-r3","3.6.3-r4","3.6.3-r5","3.6.3-r6","3.6.3-r7","3.6.3-r8","3.6.3-r9","3.6.4-r0","3.6.4-r1","3.6.6-r0","3.6.6-r1","3.6.6-r2","3.6.6-r3","3.6.7-r0","3.6.8-r0","3.6.8-r1","3.6.8-r2","3.7.2-r0","3.7.3-r0","3.7.3-r1","3.7.4-r0","3.7.5-r0","3.7.5-r1","3.8.0-r0","3.8.1-r0","3.8.1-r1","3.8.1-r2","3.8.1-r3","3.8.2-r0","3.8.2-r1","3.8.2-r2","3.8.2-r3","3.8.2-r4","3.8.2-r5","3.8.2-r6","3.8.2-r7","3.8.3-r0","3.8.4-r0","3.8.5-r0","3.8.5-r1","3.8.5-r2","3.8.6-r0","3.8.7-r0","3.8.7-r1","3.8.7-r2","3.8.7-r3","3.8.8-r0","3.9.1-r0","3.9.2-r0","3.9.4-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"}]}],"versions":["3.1.3-r0","3.2.0-r0","3.2.3-r0","3.3.0-r0","3.3.2-r0","3.3.3-r0","3.3.4-r0","3.4.1-r0","3.4.2-r0","3.4.2-r1","3.4.3-r1","3.4.3-r2","3.5.0-r0","3.5.1-r0","3.5.1-r1","3.5.1-r2","3.5.1-r3","3.5.2-r0","3.5.2-r1","3.5.2-r10","3.5.2-r2","3.5.2-r3","3.5.2-r4","3.5.2-r5","3.5.2-r6","3.5.2-r7","3.5.2-r8","3.5.2-r9","3.6.0-r0","3.6.1-r0","3.6.1-r1","3.6.1-r2","3.6.1-r3","3.6.1-r4","3.6.2-r0","3.6.2-r1","3.6.2-r2","3.6.2-r3","3.6.3-r3","3.6.3-r4","3.6.3-r5","3.6.3-r6","3.6.3-r7","3.6.3-r8","3.6.3-r9","3.6.4-r0","3.6.4-r1","3.6.6-r0","3.6.6-r1","3.6.6-r2","3.6.6-r3","3.6.7-r0","3.6.8-r0","3.6.8-r1","3.6.8-r2","3.7.2-r0","3.7.3-r0","3.7.3-r1","3.7.4-r0","3.7.5-r0","3.7.5-r1","3.8.0-r0","3.8.1-r0","3.8.1-r1","3.8.1-r2","3.8.1-r3","3.8.2-r0","3.8.2-r1","3.8.2-r2","3.8.2-r3","3.8.2-r4","3.8.2-r5","3.8.2-r6","3.8.2-r7","3.8.3-r0","3.8.4-r0","3.8.5-r0","3.8.5-r1","3.8.5-r2","3.8.6-r0","3.8.7-r0","3.8.7-r1","3.8.7-r2","3.8.7-r3","3.8.8-r0","3.9.1-r0","3.9.2-r0","3.9.4-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"}]}],"versions":["3.1.3-r0","3.2.0-r0","3.2.3-r0","3.3.0-r0","3.3.2-r0","3.3.3-r0","3.3.4-r0","3.4.1-r0","3.4.2-r0","3.4.2-r1","3.4.3-r1","3.4.3-r2","3.5.0-r0","3.5.1-r0","3.5.1-r1","3.5.1-r2","3.5.1-r3","3.5.2-r0","3.5.2-r1","3.5.2-r10","3.5.2-r2","3.5.2-r3","3.5.2-r4","3.5.2-r5","3.5.2-r6","3.5.2-r7","3.5.2-r8","3.5.2-r9","3.6.0-r0","3.6.1-r0","3.6.1-r1","3.6.1-r2","3.6.1-r3","3.6.1-r4","3.6.2-r0","3.6.2-r1","3.6.2-r2","3.6.2-r3","3.6.3-r3","3.6.3-r4","3.6.3-r5","3.6.3-r6","3.6.3-r7","3.6.3-r8","3.6.3-r9","3.6.4-r0","3.6.4-r1","3.6.6-r0","3.6.6-r1","3.6.6-r2","3.6.6-r3","3.6.7-r0","3.6.8-r0","3.6.8-r1","3.6.8-r2","3.7.2-r0","3.7.3-r0","3.7.3-r1","3.7.4-r0",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