Vulnerability-Lookup

OESA-2021-1260 (CVE-2021-33503)

Vulnerability from osv_openeuler – Published: 2021-07-10 11:04 – Updated: 2026-08-06 11:04 – Source website

Summary

python-urllib3 security update

Details

Security Fix(es):

An issue was discovered in urllib3 before 1.26.5. When provided with a URL containing many @ characters in the authority component, the authority regular expression exhibits catastrophic backtracking, causing a denial of service if a URL were passed as a parameter or redirected to via an HTTP redirect.(CVE-2021-33503)

Severity

3.3 (Low)


                    
                      CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

References

URL

Type

	https://openeuler.org/en/security/safety-bulletin…	ADVISORY
	https://nvd.nist.gov/vuln/detail/CVE-2021-33503	ADVISORY

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "noarch": [
          "python2-urllib3-1.25.9-3.oe1.noarch.rpm",
          "python3-urllib3-1.25.9-3.oe1.noarch.rpm"
        ],
        "src": [
          "python-urllib3-1.25.9-3.oe1.src.rpm"
        ]
      },
      "package": {
        "ecosystem": "openEuler:20.03-LTS-SP1",
        "name": "python-urllib3",
        "purl": "pkg:rpm/openEuler/python-urllib3\u0026distro=openEuler-20.03-LTS-SP1"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.25.9-3.oe1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "severity": "High"
  },
  "details": "\r\n\r\nSecurity Fix(es):\r\n\r\nAn issue was discovered in urllib3 before 1.26.5. When provided with a URL containing many @ characters in the authority component, the authority regular expression exhibits catastrophic backtracking, causing a denial of service if a URL were passed as a parameter or redirected to via an HTTP redirect.(CVE-2021-33503)",
  "id": "OESA-2021-1260",
  "modified": "2026-08-06T11:04:30Z",
  "published": "2021-07-10T11:04:30Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://openeuler.org/en/security/safety-bulletin/detail.html?id=openEuler-SA-2021-1260"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2021-33503"
    }
  ],
  "schema_version": "1.7.2",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "python-urllib3 security update",
  "upstream": [
    "CVE-2021-33503"
  ]
}

CVE-2021-33503 (GCVE-0-2021-33503)

Vulnerability from cvelistv5 – Published: 2021-06-29 10:55 – Updated: 2024-08-03 23:50

Summary

Severity

No CVSS data available.

CWE

Assigner

mitre CNA under the mitre root

CNA scorecard E 28/100 over 2319 records in the last 180 days details

References

6 references

URL	Tags
https://lists.fedoraproject.org/archives/list/pac…	vendor-advisoryx_refsource_FEDORA
https://lists.fedoraproject.org/archives/list/pac…	vendor-advisoryx_refsource_FEDORA
https://security.gentoo.org/glsa/202107-36	vendor-advisoryx_refsource_GENTOO
https://www.oracle.com/security-alerts/cpuoct2021.html	x_refsource_MISC
https://github.com/advisories/GHSA-q2q7-5pp4-w6pg	x_refsource_CONFIRM
https://github.com/urllib3/urllib3/commit/2d4a3fe…	x_refsource_CONFIRM

Show details on NVD website

JSON

To clipboard

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Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

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