{"schema_version":"1.8.0","id":"CVE-2021-3733","published":"2022-03-10T17:42:59.623Z","modified":"2026-08-07T11:48:56.889731678Z","aliases":["BIT-libpython-2021-3733","BIT-python-2021-3733","BIT-python-min-2021-3733","PSF-2022-6"],"related":["ALSA-2021:4160","ALSA-2022:1764","ALSA-2022:1821","SUSE-SU-2021:3477-1","SUSE-SU-2021:3486-1","SUSE-SU-2021:3489-1","SUSE-SU-2021:3524-1","SUSE-SU-2021:4015-1","SUSE-SU-2021:4015-2","SUSE-SU-2021:4104-1","SUSE-SU-2022:1485-1","openSUSE-SU-2021:1418-1","openSUSE-SU-2021:3489-1","openSUSE-SU-2021:4104-1","openSUSE-SU-2024:11202-1","openSUSE-SU-2024:11284-1","openSUSE-SU-2024:11286-1"],"details":"There's a flaw in urllib's AbstractBasicAuthHandler class. An attacker who controls a malicious HTTP server that an HTTP client (such as web browser) connects to, could trigger a Regular Expression Denial of Service (ReDOS) during an authentication request with a specially crafted payload that is sent by the server to the client. The greatest threat that this flaw poses is to application availability.","affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/python/cpython","events":[{"introduced":"0"},{"fixed":"9a0099d1bf14bce417370aae6d55527417cda354"},{"introduced":"1bf9cc509326bc42cd8cb1650eb9bf64550d817e"},{"fixed":"9da28d2b3429d1bb30e082e4c9cb544d81fdae20"},{"introduced":"fa919fdf2583bdfead1df00e842f24f30b2a34bf"},{"fixed":"3d8993a744813c5144851da5347d7b4b1885f234"},{"introduced":"9cf6752276e6fcfd0c23fdb064ad27f448aaaf75"},{"fixed":"0a7dcbdb13f1f2ab6e76e1cff47e80fb263f5da0"},{"introduced":"b494f5935c92951e75597bfe1c8b1f3112fec270"},{"last_affected":"b494f5935c92951e75597bfe1c8b1f3112fec270"},{"fixed":"7215d1ae25525c92b026166f9d5cac85fb"}],"database_specific":{"cpe":["cpe:2.3:a:python:python:*:*:*:*:*:*:*:*","cpe:2.3:a:python:python:3.10.0:-:*:*:*:*:*:*"],"extracted_events":[{"introduced":"0"},{"fixed":"3.6.14"},{"introduced":"3.7.0"},{"fixed":"3.7.11"},{"introduced":"3.8.0"},{"fixed":"3.8.10"},{"introduced":"3.9.0"},{"fixed":"3.9.5"},{"introduced":"3.10.0-NA"},{"last_affected":"3.10.0-NA"}],"source":["CPE_RANGE","CPE_STRING","REFERENCES"]}}],"versions":["3.10.0-NA","v3.10.0","v3.9.2","v3.8.8","v3.9.2rc1","v3.8.8rc1","v3.6.13","v3.7.10","v3.6.12","v3.7.9","v3.9.0b5","v3.8.5","v3.7.8","v3.6.11","v3.6.11rc1","v3.7.8rc1","v3.9.0b3","v3.9.0b1","v3.8.3","v3.8.3rc1","v3.7.7rc1","v3.9.0a2","v3.6.10","v3.6.10rc1","v3.7.6rc1","v3.8.0rc1","v3.6.9","v3.6.9rc1","v3.7.3rc1","v3.6.8","v3.7.2rc1","v3.6.8rc1","v3.7.0rc1","v3.6.6rc1","v3.7.0b5","v3.7.0b4","v3.7.0b3","v3.7.0b2","v3.7.0b1","v3.7.0a2","v3.6.2rc1","v3.6.0rc1","v3.6.0b4","v3.6.0b3","v3.6.0b1","v3.6.0a3","v3.5.0b1","v3.5.0a4","v3.5.0a3","v3.5.0a2","v3.5.0a1","v3.4.0b3","v3.4.0b2","v3.4.0b1","v3.4.0a4","v3.4.0a3","v3.4.0a2","v3.4.0a1","v3.3.0rc3","v3.3.0rc2","v3.3.0rc1","v3.3.0b2","v3.3.0b1","v3.3.0a4","v3.3.0a3","v3.3.0a2","v3.2rc3","v3.2rc2","v3.2rc1","v3.2b2","v3.2b1","v3.2a4","v3.2a3","v3.2a2","v3.2a1","v3.1","v3.1rc2","v3.1rc1","v3.1b1","v3.1a2","v3.1a1","v3.0rc3","v3.0rc2","v3.0rc1","v3.0b3","v3.0b2","v3.0b1","v3.0a5","v3.0a4","v3.0a3","v3.0a2","v3.0a1","v2.4","v2.4c1","v2.4b2","v2.4b1","v2.4a3","v2.4a2","v2.4a1","v2.3c2","v2.3c1","v2.2a3","v2.1","v2.1c2","v2.1c1","v2.1b2","v2.1b1","v2.1a2","v2.1a1","v2.0","v2.0c1","v2.0b2","v2.0b1","v1.6a2","v1.6a1","v1.5.2","v1.5.2c1","v1.5.2b2","v1.5.2b1","v1.5.2a2","v1.5.2a1","v1.5.1","v1.5","v1.5b2","v1.5b1","v1.5a4","v1.5a3","v1.5a2","v1.5a1","v1.4","v1.4b3","v1.4b2","v1.4b1","v1.3","v1.3b1","v1.2","v1.2b4","v1.2b3","v1.2b2","v1.2b1","v1.1.1","v1.1","v1.0.2","v1.0.1","v0.9.9","v0.9.8"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-3733.json"}}],"references":[{"type":"WEB","url":"https://lists.debian.org/debian-lts-announce/2023/05/msg00024.html"},{"type":"WEB","url":"https://lists.debian.org/debian-lts-announce/2023/06/msg00039.html"},{"type":"WEB","url":"https://lists.debian.org/debian-lts-announce/2024/12/msg00000.html"},{"type":"ADVISORY","url":"https://security.netapp.com/advisory/ntap-20220407-0001/"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=1995234"},{"type":"FIX","url":"https://bugs.python.org/issue43075"},{"type":"FIX","url":"https://github.com/python/cpython/commit/7215d1ae25525c92b026166f9d5cac85fb"},{"type":"FIX","url":"https://github.com/python/cpython/pull/24391"},{"type":"FIX","url":"https://ubuntu.com/security/CVE-2021-3733"}],"database_specific":{"unresolved_ranges":[{"cpes":["cpe:2.3:a:fedoraproject:extra_packages_for_enterprise_linux:7.0:*:*:*:*:*:*:*"],"extracted_events":[{"introduced":"7.0"},{"last_affected":"7.0"}],"source":"CPE_STRING","vendor_product":"fedoraproject:extra_packages_for_enterprise_linux"},{"cpes":["cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*","cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*","cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*","cpe:2.3:o:fedoraproject:fedora:36:*:*:*:*:*:*:*"],"extracted_events":[{"introduced":"33"},{"last_affected":"33"},{"introduced":"34"},{"last_affected":"34"},{"introduced":"35"},{"last_affected":"35"},{"introduced":"36"},{"last_affected":"36"}],"source":"CPE_STRING","vendor_product":"fedoraproject:fedora"},{"cpes":["cpe:2.3:a:redhat:codeready_linux_builder:8.0:*:*:*:*:*:*:*"],"extracted_events":[{"introduced":"8.0"},{"last_affected":"8.0"}],"source":"CPE_STRING","vendor_product":"redhat:codeready_linux_builder"},{"cpes":["cpe:2.3:a:redhat:codeready_linux_builder_for_ibm_z_systems:8.0:*:*:*:*:*:*:*"],"extracted_events":[{"introduced":"8.0"},{"last_affected":"8.0"}],"source":"CPE_STRING","vendor_product":"redhat:codeready_linux_builder_for_ibm_z_systems"},{"cpes":["cpe:2.3:a:redhat:codeready_linux_builder_for_power_little_endian:8.0:*:*:*:*:*:*:*"],"extracted_events":[{"introduced":"8.0"},{"last_affected":"8.0"}],"source":"CPE_STRING","vendor_product":"redhat:codeready_linux_builder_for_power_little_endian"},{"cpes":["cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*"],"extracted_events":[{"introduced":"8.0"},{"last_affected":"8.0"}]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