UBUNTU-CVE-2021-3733
- Source
- https://ubuntu.com/security/CVE-2021-3733
- Import Source
- https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-3733.json
- JSON Data
- https://api.test.osv.dev/v1/vulns/UBUNTU-CVE-2021-3733
- Upstream
- Downstream
- Related
- Published
- 2021-09-02T00:00:00Z
- Modified
- 2025-09-08T16:46:47Z
- Severity
-
- 6.5 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
- Ubuntu - medium
- Summary
- [none]
- 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.
- References
-
- https://ubuntu.com/security/CVE-2021-3733
- https://bugs.python.org/issue43075
- https://github.com/python/cpython/pull/24391
- https://github.com/python/cpython/commit/7215d1ae25525c92b026166f9d5cac85fb1defe1
- https://github.com/python/cpython/commit/a21d4fbd549ec9685068a113660553d7f80d9b09
- https://github.com/python/cpython/commit/e7654b6046090914a8323931ed759a94a5f85d60
- https://github.com/python/cpython/commit/ada14995870abddc277addf57dd690a2af04c2da
- https://github.com/python/cpython/commit/3fbe96123aeb66664fa547a8f6022efa2dc8788f
- https://ubuntu.com/security/notices/USN-5083-1
- https://ubuntu.com/security/notices/USN-5199-1
- https://ubuntu.com/security/notices/USN-5200-1
- https://www.cve.org/CVERecord?id=CVE-2021-3733
- https://ubuntu.com/security/notices/USN-6891-1
Affected packages
Ubuntu:18.04:LTS
python3.6
Package
- Name
- python3.6
- Purl
- pkg:deb/ubuntu/python3.6@3.6.9-1~18.04ubuntu1.6?arch=source&distro=bionic
Affected ranges
- Type
- ECOSYSTEM
- Events
-
Introduced0Unknown introduced version / All previous versions are affectedFixed3.6.9-1~18.04ubuntu1.6
Affected versions
3.*
3.6.3-1ubuntu1
3.6.4~rc1-1
3.6.4~rc1-2
3.6.4-1
3.6.4-2
3.6.4-3build1
3.6.4-4
3.6.5~rc1-1
3.6.5-3
3.6.6-1~18.04
3.6.7-1~18.04
3.6.8-1~18.04.1
3.6.8-1~18.04.2
3.6.8-1~18.04.3
3.6.9-1~18.04
3.6.9-1~18.04ubuntu1
3.6.9-1~18.04ubuntu1.1
3.6.9-1~18.04ubuntu1.3
3.6.9-1~18.04ubuntu1.4
Ecosystem specific
{
"availability": "No subscription required",
"binaries": [
{
"binary_version": "3.6.9-1~18.04ubuntu1.6",
"binary_name": "idle-python3.6"
},
{
"binary_version": "3.6.9-1~18.04ubuntu1.6",
"binary_name": "libpython3.6"
},
{
"binary_version": "3.6.9-1~18.04ubuntu1.6",
"binary_name": "libpython3.6-dev"
},
{
"binary_version": "3.6.9-1~18.04ubuntu1.6",
"binary_name": "libpython3.6-minimal"
},
{
"binary_version": "3.6.9-1~18.04ubuntu1.6",
"binary_name": "libpython3.6-stdlib"
},
{
"binary_version": "3.6.9-1~18.04ubuntu1.6",
"binary_name": "libpython3.6-testsuite"
},
{
"binary_version": "3.6.9-1~18.04ubuntu1.6",
"binary_name": "python3.6"
},
{
"binary_version": "3.6.9-1~18.04ubuntu1.6",
"binary_name": "python3.6-dev"
},
{
"binary_version": "3.6.9-1~18.04ubuntu1.6",
"binary_name": "python3.6-examples"
},
{
"binary_version": "3.6.9-1~18.04ubuntu1.6",
"binary_name": "python3.6-minimal"
},
{
"binary_version": "3.6.9-1~18.04ubuntu1.6",
"binary_name": "python3.6-venv"
}
]
}python3.7
Package
- Name
- python3.7
- Purl
- pkg:deb/ubuntu/python3.7@3.7.5-2ubuntu1~18.04.2?arch=source&distro=bionic
Affected ranges
- Type
- ECOSYSTEM
- Events
-
Introduced0Unknown introduced version / All previous versions are affectedFixed3.7.5-2ubuntu1~18.04.2
Affected versions
3.*
3.7.0~a2-1
3.7.0~a3-1
3.7.0~a3-2
3.7.0~a3-3
3.7.0~a4-1
3.7.0~b1-1
3.7.0~b1-1build1
3.7.0~b2-1
3.7.0~b3-1
3.7.0-1~18.04
3.7.1-1~18.04
3.7.3-2~18.04.1
3.7.5-2~18.04
3.7.5-2~18.04.4
Ecosystem specific
{
"availability": "No subscription required",
"binaries": [
{
"binary_version": "3.7.5-2ubuntu1~18.04.2",
"binary_name": "idle-python3.7"
},
{
"binary_version": "3.7.5-2ubuntu1~18.04.2",
"binary_name": "libpython3.7"
},
{
"binary_version": "3.7.5-2ubuntu1~18.04.2",
"binary_name": "libpython3.7-dev"
},
{
"binary_version": "3.7.5-2ubuntu1~18.04.2",
"binary_name": "libpython3.7-minimal"
},
{
"binary_version": "3.7.5-2ubuntu1~18.04.2",
"binary_name": "libpython3.7-stdlib"
},
{
"binary_version": "3.7.5-2ubuntu1~18.04.2",
"binary_name": "libpython3.7-testsuite"
},
{
"binary_version": "3.7.5-2ubuntu1~18.04.2",
"binary_name": "python3.7"
},
{
"binary_version": "3.7.5-2ubuntu1~18.04.2",
"binary_name": "python3.7-dev"
},
{
"binary_version": "3.7.5-2ubuntu1~18.04.2",
"binary_name": "python3.7-examples"
},
{
"binary_version": "3.7.5-2ubuntu1~18.04.2",
"binary_name": "python3.7-minimal"
},
{
"binary_version": "3.7.5-2ubuntu1~18.04.2",
"binary_name": "python3.7-venv"
}
]
}python3.8
Package
- Name
- python3.8
- Purl
- pkg:deb/ubuntu/python3.8@3.8.0-3ubuntu1~18.04.2?arch=source&distro=bionic
Affected ranges
- Type
- ECOSYSTEM
- Events
-
Introduced0Unknown introduced version / All previous versions are affectedFixed3.8.0-3ubuntu1~18.04.2
Ecosystem specific
{
"availability": "No subscription required",
"binaries": [
{
"binary_version": "3.8.0-3ubuntu1~18.04.2",
"binary_name": "idle-python3.8"
},
{
"binary_version": "3.8.0-3ubuntu1~18.04.2",
"binary_name": "libpython3.8"
},
{
"binary_version": "3.8.0-3ubuntu1~18.04.2",
"binary_name": "libpython3.8-dev"
},
{
"binary_version": "3.8.0-3ubuntu1~18.04.2",
"binary_name": "libpython3.8-minimal"
},
{
"binary_version": "3.8.0-3ubuntu1~18.04.2",
"binary_name": "libpython3.8-stdlib"
},
{
"binary_version": "3.8.0-3ubuntu1~18.04.2",
"binary_name": "libpython3.8-testsuite"
},
{
"binary_version": "3.8.0-3ubuntu1~18.04.2",
"binary_name": "python3.8"
},
{
"binary_version": "3.8.0-3ubuntu1~18.04.2",
"binary_name": "python3.8-dev"
},
{
"binary_version": "3.8.0-3ubuntu1~18.04.2",
"binary_name": "python3.8-examples"
},
{
"binary_version": "3.8.0-3ubuntu1~18.04.2",
"binary_name": "python3.8-minimal"
},
{
"binary_version": "3.8.0-3ubuntu1~18.04.2",
"binary_name": "python3.8-venv"
}
]
}Ubuntu:20.04:LTS
python3.8
Package
- Name
- python3.8
- Purl
- pkg:deb/ubuntu/python3.8@3.8.10-0ubuntu1~20.04?arch=source&distro=focal
Affected ranges
- Type
- ECOSYSTEM
- Events
-
Introduced0Unknown introduced version / All previous versions are affectedFixed3.8.10-0ubuntu1~20.04
Affected versions
3.*
3.8.0-1
3.8.0-2
3.8.0-3
3.8.0-4
3.8.0-5
3.8.1-2ubuntu3
3.8.2~rc1-1ubuntu1
3.8.2-1
3.8.2-1ubuntu1
3.8.2-1ubuntu1.1
3.8.2-1ubuntu1.2
3.8.5-1~20.04
3.8.5-1~20.04.2
3.8.5-1~20.04.3
Ecosystem specific
{
"availability": "No subscription required",
"binaries": [
{
"binary_version": "3.8.10-0ubuntu1~20.04",
"binary_name": "idle-python3.8"
},
{
"binary_version": "3.8.10-0ubuntu1~20.04",
"binary_name": "libpython3.8"
},
{
"binary_version": "3.8.10-0ubuntu1~20.04",
"binary_name": "libpython3.8-dev"
},
{
"binary_version": "3.8.10-0ubuntu1~20.04",
"binary_name": "libpython3.8-minimal"
},
{
"binary_version": "3.8.10-0ubuntu1~20.04",
"binary_name": "libpython3.8-stdlib"
},
{
"binary_version": "3.8.10-0ubuntu1~20.04",
"binary_name": "libpython3.8-testsuite"
},
{
"binary_version": "3.8.10-0ubuntu1~20.04",
"binary_name": "python3.8"
},
{
"binary_version": "3.8.10-0ubuntu1~20.04",
"binary_name": "python3.8-dev"
},
{
"binary_version": "3.8.10-0ubuntu1~20.04",
"binary_name": "python3.8-examples"
},
{
"binary_version": "3.8.10-0ubuntu1~20.04",
"binary_name": "python3.8-full"
},
{
"binary_version": "3.8.10-0ubuntu1~20.04",
"binary_name": "python3.8-minimal"
},
{
"binary_version": "3.8.10-0ubuntu1~20.04",
"binary_name": "python3.8-venv"
}
]
}python3.9
Package
- Name
- python3.9
- Purl
- pkg:deb/ubuntu/python3.9@3.9.5-3~20.04.1?arch=source&distro=focal
Affected ranges
- Type
- ECOSYSTEM
- Events
-
Introduced0Unknown introduced version / All previous versions are affectedFixed3.9.5-3~20.04.1
Ecosystem specific
{
"availability": "No subscription required",
"binaries": [
{
"binary_version": "3.9.5-3~20.04.1",
"binary_name": "idle-python3.9"
},
{
"binary_version": "3.9.5-3~20.04.1",
"binary_name": "libpython3.9"
},
{
"binary_version": "3.9.5-3~20.04.1",
"binary_name": "libpython3.9-dev"
},
{
"binary_version": "3.9.5-3~20.04.1",
"binary_name": "libpython3.9-minimal"
},
{
"binary_version": "3.9.5-3~20.04.1",
"binary_name": "libpython3.9-stdlib"
},
{
"binary_version": "3.9.5-3~20.04.1",
"binary_name": "libpython3.9-testsuite"
},
{
"binary_version": "3.9.5-3~20.04.1",
"binary_name": "python3.9"
},
{
"binary_version": "3.9.5-3~20.04.1",
"binary_name": "python3.9-dev"
},
{
"binary_version": "3.9.5-3~20.04.1",
"binary_name": "python3.9-examples"
},
{
"binary_version": "3.9.5-3~20.04.1",
"binary_name": "python3.9-full"
},
{
"binary_version": "3.9.5-3~20.04.1",
"binary_name": "python3.9-minimal"
},
{
"binary_version": "3.9.5-3~20.04.1",
"binary_name": "python3.9-venv"
}
]
}Ubuntu:Pro:14.04:LTS
python3.4
Package
- Name
- python3.4
- Purl
- pkg:deb/ubuntu/python3.4@3.4.3-1ubuntu1~14.04.7+esm11?arch=source&distro=trusty/esm
Affected ranges
- Type
- ECOSYSTEM
- Events
-
Introduced0Unknown introduced version / All previous versions are affectedFixed3.4.3-1ubuntu1~14.04.7+esm11
Affected versions
3.*
3.4~b1-0ubuntu3
3.4~b1-4ubuntu4
3.4~b1-4ubuntu6
3.4~b1-5ubuntu2
3.4~b2-1
3.4~b3-1ubuntu1
3.4~rc1-1build1
3.4~rc2-1
3.4~rc3-0ubuntu1
3.4.0-1
3.4.0-2ubuntu1
3.4.0-2ubuntu1.1
3.4.3-1ubuntu1~14.04.1
3.4.3-1ubuntu1~14.04.3
3.4.3-1ubuntu1~14.04.4
3.4.3-1ubuntu1~14.04.5
3.4.3-1ubuntu1~14.04.6
3.4.3-1ubuntu1~14.04.7
3.4.3-1ubuntu1~14.04.7+esm2
3.4.3-1ubuntu1~14.04.7+esm4
3.4.3-1ubuntu1~14.04.7+esm6
3.4.3-1ubuntu1~14.04.7+esm7
3.4.3-1ubuntu1~14.04.7+esm8
3.4.3-1ubuntu1~14.04.7+esm10
Ecosystem specific
{
"availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro",
"binaries": [
{
"binary_version": "3.4.3-1ubuntu1~14.04.7+esm11",
"binary_name": "idle-python3.4"
},
{
"binary_version": "3.4.3-1ubuntu1~14.04.7+esm11",
"binary_name": "libpython3.4"
},
{
"binary_version": "3.4.3-1ubuntu1~14.04.7+esm11",
"binary_name": "libpython3.4-dev"
},
{
"binary_version": "3.4.3-1ubuntu1~14.04.7+esm11",
"binary_name": "libpython3.4-minimal"
},
{
"binary_version": "3.4.3-1ubuntu1~14.04.7+esm11",
"binary_name": "libpython3.4-stdlib"
},
{
"binary_version": "3.4.3-1ubuntu1~14.04.7+esm11",
"binary_name": "libpython3.4-testsuite"
},
{
"binary_version": "3.4.3-1ubuntu1~14.04.7+esm11",
"binary_name": "python3.4"
},
{
"binary_version": "3.4.3-1ubuntu1~14.04.7+esm11",
"binary_name": "python3.4-dev"
},
{
"binary_version": "3.4.3-1ubuntu1~14.04.7+esm11",
"binary_name": "python3.4-examples"
},
{
"binary_version": "3.4.3-1ubuntu1~14.04.7+esm11",
"binary_name": "python3.4-minimal"
},
{
"binary_version": "3.4.3-1ubuntu1~14.04.7+esm11",
"binary_name": "python3.4-venv"
}
]
}python3.5
Package
- Name
- python3.5
- Purl
- pkg:deb/ubuntu/python3.5@3.5.2-2ubuntu0~16.04.4~14.04.1+esm1?arch=source&distro=trusty/esm
Affected ranges
- Type
- ECOSYSTEM
- Events
-
Introduced0Unknown introduced version / All previous versions are affectedFixed3.5.2-2ubuntu0~16.04.4~14.04.1+esm1
Ecosystem specific
{
"availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro",
"binaries": [
{
"binary_version": "3.5.2-2ubuntu0~16.04.4~14.04.1+esm1",
"binary_name": "idle-python3.5"
},
{
"binary_version": "3.5.2-2ubuntu0~16.04.4~14.04.1+esm1",
"binary_name": "libpython3.5"
},
{
"binary_version": "3.5.2-2ubuntu0~16.04.4~14.04.1+esm1",
"binary_name": "libpython3.5-dev"
},
{
"binary_version": "3.5.2-2ubuntu0~16.04.4~14.04.1+esm1",
"binary_name": "libpython3.5-minimal"
},
{
"binary_version": "3.5.2-2ubuntu0~16.04.4~14.04.1+esm1",
"binary_name": "libpython3.5-stdlib"
},
{
"binary_version": "3.5.2-2ubuntu0~16.04.4~14.04.1+esm1",
"binary_name": "libpython3.5-testsuite"
},
{
"binary_version": "3.5.2-2ubuntu0~16.04.4~14.04.1+esm1",
"binary_name": "python3.5"
},
{
"binary_version": "3.5.2-2ubuntu0~16.04.4~14.04.1+esm1",
"binary_name": "python3.5-dev"
},
{
"binary_version": "3.5.2-2ubuntu0~16.04.4~14.04.1+esm1",
"binary_name": "python3.5-examples"
},
{
"binary_version": "3.5.2-2ubuntu0~16.04.4~14.04.1+esm1",
"binary_name": "python3.5-minimal"
},
{
"binary_version": "3.5.2-2ubuntu0~16.04.4~14.04.1+esm1",
"binary_name": "python3.5-venv"
}
]
}Ubuntu:Pro:16.04:LTS
python3.5
Package
- Name
- python3.5
- Purl
- pkg:deb/ubuntu/python3.5@3.5.2-2ubuntu0~16.04.13+esm1?arch=source&distro=esm-infra/xenial
Affected ranges
- Type
- ECOSYSTEM
- Events
-
Introduced0Unknown introduced version / All previous versions are affectedFixed3.5.2-2ubuntu0~16.04.13+esm1
Affected versions
3.*
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
Ecosystem specific
{
"availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro",
"binaries": [
{
"binary_version": "3.5.2-2ubuntu0~16.04.13+esm1",
"binary_name": "idle-python3.5"
},
{
"binary_version": "3.5.2-2ubuntu0~16.04.13+esm1",
"binary_name": "libpython3.5"
},
{
"binary_version": "3.5.2-2ubuntu0~16.04.13+esm1",
"binary_name": "libpython3.5-dev"
},
{
"binary_version": "3.5.2-2ubuntu0~16.04.13+esm1",
"binary_name": "libpython3.5-minimal"
},
{
"binary_version": "3.5.2-2ubuntu0~16.04.13+esm1",
"binary_name": "libpython3.5-stdlib"
},
{
"binary_version": "3.5.2-2ubuntu0~16.04.13+esm1",
"binary_name": "libpython3.5-testsuite"
},
{
"binary_version": "3.5.2-2ubuntu0~16.04.13+esm1",
"binary_name": "python3.5"
},
{
"binary_version": "3.5.2-2ubuntu0~16.04.13+esm1",
"binary_name": "python3.5-dev"
},
{
"binary_version": "3.5.2-2ubuntu0~16.04.13+esm1",
"binary_name": "python3.5-examples"
},
{
"binary_version": "3.5.2-2ubuntu0~16.04.13+esm1",
"binary_name": "python3.5-minimal"
},
{
"binary_version": "3.5.2-2ubuntu0~16.04.13+esm1",
"binary_name": "python3.5-venv"
}
]
}