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Medium

CVE-2021-23336 affecting package python-py 1.11.0-1

Type: advisorySources: OSV

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
python-py
Affected versions
Not specified
Fixed versions
Not specified
CVEs
CVE-2021-23336
Confirmed fixed CVEs
Not specified
Updated in this feed
1 Nov 2026, 17:27 UTC · Revision 1

Source evidence

CVE-2021-23336 affecting package python-py 1.11.0-1

core-osv · Original source

Published 15 Feb 2021, 13:15 UTC

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:AZL-109632

python-py

Fixed versions: Not specified

Complete source record
{
  "id": "f129d71b5c64dc2800b5c611d3befcc02024dd1a3e3a1b1fb8e0995684d5caf2",
  "url": "https://osv.dev/vulnerability/AZL-109632",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2021-23336 affecting package python-py 1.11.0-1",
    "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:AZL-109632",
    "products": [
      {
        "name": {
          "value": "python-py",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": []
      }
    ],
    "severity": "medium",
    "structured": {
      "id": "AZL-109632",
      "aliases": [
        "AZL-109632"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "last_affected": "1.11.0-1"
                }
              ]
            }
          ],
          "package": {
            "name": "python-py",
            "purl": "pkg:rpm/azure-linux/python-py",
            "ecosystem": "Azure Linux:3"
          },
          "database_specific": {
            "source": "https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-109632.json"
          }
        }
      ],
      "modified": "2026-10-27T05:36:16Z",
      "provider": "osv",
      "upstream": [
        "CVE-2021-23336"
      ],
      "references": [
        "https://nvd.nist.gov/vuln/detail/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": 460507,
  "published_at": "2021-02-15T13:15:12+00:00"
}