{"id":"UBUNTU-CVE-2021-28861","details":"Python 3.x through 3.10 has an open redirection vulnerability in lib/http/server.py due to no protection against multiple (/) at the beginning of URI path which may leads to information disclosure. NOTE: this is disputed by a third party because the http.server.html documentation page states \"Warning: http.server is not recommended for production. It only implements basic security checks.\"","modified":"2026-04-22T14:40:38.204248Z","published":"2022-08-23T01:15:00Z","related":["USN-5629-1","USN-5888-1"],"upstream":["CVE-2021-28861"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2021-28861"},{"type":"REPORT","url":"https://github.com/python/cpython/pull/93879"},{"type":"REPORT","url":"https://github.com/python/cpython/pull/24848"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-5629-1"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-5888-1"},{"type":"REPORT","url":"https://python-security.readthedocs.io/vuln/http-server-redirection.html"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2021-28861"}],"affected":[{"package":{"name":"python3.5","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/python3.5@3.5.2-2ubuntu0~16.04.13+esm5?arch=source&distro=esm-infra/xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.5.2-2ubuntu0~16.04.13+esm5"}]}],"versions":["3.5.0-3","3.5.0-3ubuntu1","3.5.1~rc1-2ubuntu1","3.5.1-1","3.5.1-2","3.5.1-3","3.5.1-5","3.5.1-6ubuntu1","3.5.1-6ubuntu2","3.5.1-9ubuntu1","3.5.1-10","3.5.2-2~16.01","3.5.2-2~16.04","3.5.2-2ubuntu0~16.04.1","3.5.2-2ubuntu0~16.04.2","3.5.2-2ubuntu0~16.04.3","3.5.2-2ubuntu0~16.04.4","3.5.2-2ubuntu0~16.04.5","3.5.2-2ubuntu0~16.04.8","3.5.2-2ubuntu0~16.04.9","3.5.2-2ubuntu0~16.04.10","3.5.2-2ubuntu0~16.04.11","3.5.2-2ubuntu0~16.04.12","3.5.2-2ubuntu0~16.04.13","3.5.2-2ubuntu0~16.04.13+esm1","3.5.2-2ubuntu0~16.04.13+esm2","3.5.2-2ubuntu0~16.04.13+esm3"],"ecosystem_specific":{"availability":"Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro","binaries":[{"binary_name":"idle-python3.5","binary_version":"3.5.2-2ubuntu0~16.04.13+esm5"},{"binary_name":"libpython3.5","binary_version":"3.5.2-2ubuntu0~16.04.13+esm5"},{"binary_name":"libpython3.5-minimal","binary_version":"3.5.2-2ubuntu0~16.04.13+esm5"},{"binary_name":"libpython3.5-stdlib","binary_version":"3.5.2-2ubuntu0~16.04.13+esm5"},{"binary_name":"libpython3.5-testsuite","binary_version":"3.5.2-2ubuntu0~16.04.13+esm5"},{"binary_name":"python3.5","binary_version":"3.5.2-2ubuntu0~16.04.13+esm5"},{"binary_name":"python3.5-examples","binary_version":"3.5.2-2ubuntu0~16.04.13+esm5"},{"binary_version":"3.5.2-2ubuntu0~16.04.13+esm5","binary_name":"python3.5-minimal"},{"binary_name":"python3.5-venv","binary_version":"3.5.2-2ubuntu0~16.04.13+esm5"}],"priority_reason":"Works as documented, and disputed as being a security issue"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-28861.json"}},{"package":{"name":"python3.9","ecosystem":"Ubuntu:Pro:20.04:LTS","purl":"pkg:deb/ubuntu/python3.9@3.9.5-3ubuntu0~20.04.1+esm1?arch=source&distro=esm-apps/focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.9.5-3ubuntu0~20.04.1+esm1"}]}],"versions":["3.9.0~rc1-1~20.04","3.9.0-5~20.04","3.9.5-3~20.04.1","3.9.5-3ubuntu0~20.04.1"],"ecosystem_specific":{"availability":"Available with Ubuntu Pro: https://ubuntu.com/pro","binaries":[{"binary_name":"idle-python3.9","binary_version":"3.9.5-3ubuntu0~20.04.1+esm1"},{"binary_name":"libpython3.9","binary_version":"3.9.5-3ubuntu0~20.04.1+esm1"},{"binary_name":"libpython3.9-minimal","binary_version":"3.9.5-3ubuntu0~20.04.1+esm1"},{"binary_name":"libpython3.9-stdlib","binary_version":"3.9.5-3ubuntu0~20.04.1+esm1"},{"binary_name":"libpython3.9-testsuite","binary_version":"3.9.5-3ubuntu0~20.04.1+esm1"},{"binary_name":"python3.9","binary_version":"3.9.5-3ubuntu0~20.04.1+esm1"},{"binary_version":"3.9.5-3ubuntu0~20.04.1+esm1","binary_name":"python3.9-examples"},{"binary_name":"python3.9-full","binary_version":"3.9.5-3ubuntu0~20.04.1+esm1"},{"binary_name":"python3.9-minimal","binary_version":"3.9.5-3ubuntu0~20.04.1+esm1"},{"binary_name":"python3.9-venv","binary_version":"3.9.5-3ubuntu0~20.04.1+esm1"}],"priority_reason":"Works as documented, and disputed as being a security issue"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-28861.json"}},{"package":{"name":"python3.10","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/python3.10@3.10.6-1~22.04.1?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.10.6-1~22.04.1"}]}],"versions":["3.10.0-2","3.10.0-3","3.10.0-4","3.10.0-5","3.10.0-5build1","3.10.1-1","3.10.1-2","3.10.2-1","3.10.2-5","3.10.2-7","3.10.3-1","3.10.4-3","3.10.4-3ubuntu0.1","3.10.6-1~22.04"],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_name":"idle-python3.10","binary_version":"3.10.6-1~22.04.1"},{"binary_name":"libpython3.10","binary_version":"3.10.6-1~22.04.1"},{"binary_name":"libpython3.10-minimal","binary_version":"3.10.6-1~22.04.1"},{"binary_name":"libpython3.10-stdlib","binary_version":"3.10.6-1~22.04.1"},{"binary_name":"libpython3.10-testsuite","binary_version":"3.10.6-1~22.04.1"},{"binary_name":"python3.10","binary_version":"3.10.6-1~22.04.1"},{"binary_name":"python3.10-examples","binary_version":"3.10.6-1~22.04.1"},{"binary_name":"python3.10-full","binary_version":"3.10.6-1~22.04.1"},{"binary_name":"python3.10-minimal","binary_version":"3.10.6-1~22.04.1"},{"binary_name":"python3.10-nopie","binary_version":"3.10.6-1~22.04.1"},{"binary_name":"python3.10-venv","binary_version":"3.10.6-1~22.04.1"}],"priority_reason":"Works as documented, and disputed as being a security issue"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-28861.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N"},{"type":"Ubuntu","score":"low"}]}