BREW-AIRSHARE-CVE-2020-7212 (GHSA-HMV2-79Q8-FV6G)

Vulnerability from osv_homebrew – Published: 2026-08-13 16:35 – Updated: 2026-09-09 23:40 – Source website
VLAI
Summary
Uncontrolled Resource Consumption in urllib3
Details

The _encode_invalid_chars function in util/url.py in the urllib3 library 1.25.2 through 1.25.7 for Python allows a denial of service (CPU consumption) because of an inefficient algorithm. The percent_encodings array contains all matches of percent encodings. It is not deduplicated. For a URL of length N, the size of percent_encodings may be up to O(N). The next step (normalize existing percent-encoded bytes) also takes up to O(N) for each step, so the total time is O(N^2). If percent_encodings were deduplicated, the time to compute _encode_invalid_chars would be O(kN), where k is at most 484 ((10+6*2)^2).

Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
8.7 (High)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "fix": "bump",
        "range_state": "fixed",
        "resource": "urllib3",
        "resource_purl": "pkg:pypi/urllib3@2.7.0",
        "upstream_fixed_in": "1.25.8"
      },
      "package": {
        "ecosystem": "Homebrew",
        "name": "airshare",
        "purl": "pkg:brew/airshare"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.1.6_25"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "confidence": "high",
    "source": "matched",
    "strategy": "registry",
    "upstream_evidence": [
      {
        "ecosystem": "PyPI",
        "key": "pkg:pypi/urllib3@2.7.0",
        "name": "urllib3",
        "resource": "urllib3",
        "strategy": "registry",
        "subject_version": "2.7.0"
      }
    ]
  },
  "details": "The _encode_invalid_chars function in util/url.py in the urllib3 library 1.25.2 through 1.25.7 for Python allows a denial of service (CPU consumption) because of an inefficient algorithm. The percent_encodings array contains all matches of percent encodings. It is not deduplicated. For a URL of length N, the size of percent_encodings may be up to O(N). The next step (normalize existing percent-encoded bytes) also takes up to O(N) for each step, so the total time is O(N^2). If percent_encodings were deduplicated, the time to compute _encode_invalid_chars would be O(kN), where k is at most 484 ((10+6*2)^2).",
  "id": "BREW-airshare-CVE-2020-7212",
  "modified": "2026-09-09T23:40:57Z",
  "published": "2026-08-13T16:35:13Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2020-7212"
    },
    {
      "type": "WEB",
      "url": "https://github.com/urllib3/urllib3/commit/a74c9cfbaed9f811e7563cfc3dce894928e0221a"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/advisories/GHSA-hmv2-79q8-fv6g"
    },
    {
      "type": "WEB",
      "url": "https://github.com/pypa/advisory-database/tree/main/vulns/urllib3/PYSEC-2020-149.yaml"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/urllib3/urllib3"
    },
    {
      "type": "WEB",
      "url": "https://github.com/urllib3/urllib3/blob/master/CHANGES.rst"
    },
    {
      "type": "WEB",
      "url": "https://pypi.org/project/urllib3/1.25.8"
    }
  ],
  "schema_version": "1.7.3",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Uncontrolled Resource Consumption in urllib3",
  "upstream": [
    "GHSA-hmv2-79q8-fv6g",
    "CVE-2020-7212",
    "PYSEC-2020-149"
  ]
}



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