{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "state": "PUBLISHED", "cveId": "CVE-2021-29921", "assignerOrgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca", "assignerShortName": "mitre", "dateUpdated": "2025-11-03T21:44:43.122Z", "dateReserved": "2021-04-01T00:00:00.000Z", "datePublished": "2021-05-06T00:00:00.000Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca", "shortName": "mitre", "dateUpdated": "2023-05-03T00:00:00.000Z" }, "descriptions": [ { "lang": "en", "value": "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": [ { "vendor": "n/a", "product": "n/a", "versions": [ { "version": "n/a", "status": "affected" } ] } ], "references": [ { "url": "https://github.com/sickcodes" }, { "url": "https://docs.python.org/3/library/ipaddress.html" }, { "url": "https://github.com/python/cpython/blob/63298930fb531ba2bb4f23bc3b915dbf1e17e9e1/Misc/NEWS.d/3.8.0a4.rst" }, { "url": "https://sick.codes/sick-2021-014" }, { "url": "https://www.oracle.com//security-alerts/cpujul2021.html" }, { "url": "https://github.com/sickcodes/security/blob/master/advisories/SICK-2021-014.md" }, { "url": "https://python-security.readthedocs.io/vuln/ipaddress-ipv4-leading-zeros.html" }, { "url": "https://bugs.python.org/issue36384" }, { "url": "https://github.com/python/cpython/pull/12577" }, { "url": "https://github.com/python/cpython/pull/25099" }, { "url": "https://security.netapp.com/advisory/ntap-20210622-0003/" }, { "url": "https://www.oracle.com/security-alerts/cpuoct2021.html" }, { "url": "https://www.oracle.com/security-alerts/cpujan2022.html" }, { "url": "https://www.oracle.com/security-alerts/cpuapr2022.html" }, { "url": "https://www.oracle.com/security-alerts/cpujul2022.html" }, { "name": "GLSA-202305-02", "tags": [ "vendor-advisory" ], "url": "https://security.gentoo.org/glsa/202305-02" } ], "problemTypes": [ { "descriptions": [ { "type": "text", "lang": "en", "description": "n/a" } ] } ] }, "adp": [ { "title": "CVE Program Container", "references": [ { "url": "https://github.com/sickcodes", "tags": [ "x_transferred" ] }, { "url": "https://docs.python.org/3/library/ipaddress.html", "tags": [ "x_transferred" ] }, { "url": "https://github.com/python/cpython/blob/63298930fb531ba2bb4f23bc3b915dbf1e17e9e1/Misc/NEWS.d/3.8.0a4.rst", "tags": [ "x_transferred" ] }, { "url": "https://sick.codes/sick-2021-014", "tags": [ "x_transferred" ] }, { "url": "https://www.oracle.com//security-alerts/cpujul2021.html", "tags": [ "x_transferred" ] }, { "url": "https://github.com/sickcodes/security/blob/master/advisories/SICK-2021-014.md", "tags": [ "x_transferred" ] }, { "url": "https://python-security.readthedocs.io/vuln/ipaddress-ipv4-leading-zeros.html", "tags": [ "x_transferred" ] }, { "url": "https://bugs.python.org/issue36384", "tags": [ "x_transferred" ] }, { "url": "https://github.com/python/cpython/pull/12577", "tags": [ "x_transferred" ] }, { "url": "https://github.com/python/cpython/pull/25099", "tags": [ "x_transferred" ] }, { "url": "https://security.netapp.com/advisory/ntap-20210622-0003/", "tags": [ "x_transferred" ] }, { "url": "https://www.oracle.com/security-alerts/cpuoct2021.html", "tags": [ "x_transferred" ] }, { "url": "https://www.oracle.com/security-alerts/cpujan2022.html", "tags": [ "x_transferred" ] }, { "url": "https://www.oracle.com/security-alerts/cpuapr2022.html", "tags": [ "x_transferred" ] }, { "url": "https://www.oracle.com/security-alerts/cpujul2022.html", "tags": [ "x_transferred" ] }, { "name": "GLSA-202305-02", "tags": [ "vendor-advisory", "x_transferred" ], "url": "https://security.gentoo.org/glsa/202305-02" }, { "url": "https://lists.debian.org/debian-lts-announce/2024/12/msg00000.html" } ], "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2025-11-03T21:44:43.122Z" } } ] } }