pypy3, python-django — security advisory
The package python/cpython from 0 and before 3.6.13, from 3.7.0 and before 3.7.10, from 3.8.0 and before 3.8.8, from 3.9.0 and before 3.9.2 are vulnerable to Web Cache Poisoning via urllib.parse.parse_qsl and urllib.parse.parse_qs by using a vector called parameter cloaking. When the attacker can separate query parameters using a semicolon (;), they can cause a difference in the interpretation of the request between the proxy (running with default configuration) and the server. This can result in malicious requests being cached as completely safe ones, as the proxy would usually not see the semicolon as a separator, and therefore would not include it in a cache key of an unkeyed parameter.
- Products
- pypy3, python-django
- Affected versions
- Not specified
- Fixed versions
- 2:2.2.19-1, 7.3.3+dfsg-3
- CVEs
- CVE-2021-23336
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 30 Oct 2026, 16:20 UTC · Revision 1
Source evidence
The package python/cpython from 0 and before 3.6.13, from 3.7.0 and before 3.7.10, from 3.8.0 and before 3.8.8, from 3.9.0 and before 3.9.2 are vulnerable to Web Cache Poisoning via urllib.parse.parse_qsl and urllib.parse.parse_qs by using a vector called parameter cloaking. When the attacker can separate query parameters using a semicolon (;), they can cause a difference in the interpretation of the request between the proxy (running with default configuration) and the server. This can result in malicious requests being cached as completely safe ones, as the proxy would usually not see the semicolon as a separator, and therefore would not include it in a cache key of an unkeyed parameter.
osv:DEBIAN-CVE-2021-23336
pypy3
Fixed versions: 7.3.3+dfsg-3
pypy3
Fixed versions: 7.3.3+dfsg-3
pypy3
Fixed versions: 7.3.3+dfsg-3
python-django
Fixed versions: 2:2.2.19-1
python-django
Fixed versions: 2:2.2.19-1
python-django
Fixed versions: 2:2.2.19-1
Complete source record
{
"id": "18d1ea2b900a66688b07febf287dce7f4684c7d523ab28536a45e12c6679c52d",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2021-23336",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2021-23336",
"summary": "The package python/cpython from 0 and before 3.6.13, from 3.7.0 and before 3.7.10, from 3.8.0 and before 3.8.8, from 3.9.0 and before 3.9.2 are vulnerable to Web Cache Poisoning via urllib.parse.parse_qsl and urllib.parse.parse_qs by using a vector called parameter cloaking. When the attacker can separate query parameters using a semicolon (;), they can cause a difference in the interpretation of the request between the proxy (running with default configuration) and the server. This can result in malicious requests being cached as completely safe ones, as the proxy would usually not see the semicolon as a separator, and therefore would not include it in a cache key of an unkeyed parameter.",
"evidence": "osv:DEBIAN-CVE-2021-23336",
"products": [
{
"name": {
"value": "pypy3",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
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"value": "7.3.3+dfsg-3",
"evidence": "/affected/0/ranges"
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"affected_versions": []
},
{
"name": {
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{
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{
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"evidence": "/affected/3/ranges"
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"affected_versions": []
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{
"name": {
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"affected_versions": []
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{
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],
"severity": "medium",
"structured": {
"id": "DEBIAN-CVE-2021-23336",
"aliases": [
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"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:H"
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"affected": [
{
"ranges": [
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"events": [
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"package": {
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"purl": "pkg:deb/debian/pypy3?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
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"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2021-23336.json"
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"ecosystem_specific": {
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{
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"ecosystem": "Debian:13"
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"database_specific": {
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"package": {
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"purl": "pkg:deb/debian/python-django?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
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},
"ecosystem_specific": {
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}
},
{
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"package": {
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"purl": "pkg:deb/debian/python-django?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2021-23336.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
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"type": "ECOSYSTEM",
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"introduced": "0"
},
{
"fixed": "2:2.2.19-1"
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],
"package": {
"name": "python-django",
"purl": "pkg:deb/debian/python-django?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2021-23336.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-15T09:47:30.107642116Z",
"provider": "osv",
"upstream": [
"CVE-2021-23336"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2021-23336"
]
},
"related_cves": [
{
"value": "CVE-2021-23336",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 327531,
"published_at": "2021-02-15T13:15:12.433+00:00"
}