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Medium

Security advisory

Type: advisorySources: OSVCVE: CVE-2020-28473

The package bottle from 0 and before 0.12.19 are vulnerable to Web Cache Poisoning 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
Not specified
Affected versions
Not specified
Fixed versions
Not specified
CVEs
CVE-2020-28473
Confirmed fixed CVEs
Not specified
Updated in this feed
31 Oct 2026, 11:25 UTC · Revision 1

Source evidence

CVE-2020-28473

core-osv · Original source

Published 18 Jan 2021, 12:15 UTC

The package bottle from 0 and before 0.12.19 are vulnerable to Web Cache Poisoning 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:CVE-2020-28473
Complete source record
{
  "id": "e20493d6db74eded8e79b3407eb0e74d9f7c69f0fcacc1b15a87d071e1212be3",
  "url": "https://osv.dev/vulnerability/CVE-2020-28473",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2020-28473",
    "summary": "The package bottle from 0 and before 0.12.19 are vulnerable to Web Cache Poisoning 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:CVE-2020-28473",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2020-28473",
      "aliases": [
        "CVE-2020-28473",
        "GHSA-qhx9-7hx7-cp4r",
        "PYSEC-2021-129",
        "SNYK-PYTHON-BOTTLE-1017108"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/bottlepy/bottle",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "152219818378926f20a5ee3d339118d7cf50a8f6"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:bottlepy:bottle:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "0.12.19"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "0.12.18",
            "0.12.17",
            "0.12.16",
            "0.12.15",
            "0.12.14",
            "0.12.13",
            "0.12.12",
            "0.12.11",
            "0.12.10",
            "0.12.9",
            "0.12.8",
            "0.12.7",
            "0.12.6",
            "0.12.5",
            "0.12.4",
            "0.12.3",
            "0.12.2",
            "0.12.1",
            "0.12.0",
            "0.8.0",
            "0.5.6",
            "0.5.5",
            "0.5.4",
            "0.5.3",
            "0.5.1",
            "0.4.14",
            "0.4.13",
            "0.4.12",
            "0.4.11",
            "0.4.10"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-28473.json"
          }
        }
      ],
      "modified": "2026-10-20T10:54:19.441466471Z",
      "provider": "osv",
      "references": [
        "https://lists.debian.org/debian-lts-announce/2021/01/msg00019.html",
        "https://snyk.io/blog/cache-poisoning-in-popular-open-source-packages/",
        "https://github.com/bottlepy/bottle",
        "https://snyk.io/vuln/SNYK-PYTHON-BOTTLE-1017108"
      ],
      "provider_metadata": {
        "unresolved_ranges": [
          {
            "cpes": [
              "cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*"
            ],
            "vendor_product": "debian:debian_linux",
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "9.0"
                  },
                  {
                    "last_affected": "9.0"
                  }
                ],
                "source": "CPE_STRING"
              }
            ]
          }
        ]
      }
    },
    "related_cves": [
      {
        "value": "CVE-2020-28473",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 385040,
  "published_at": "2021-01-18T12:15:12.707+00:00"
}