Vulnerability-Lookup

FKIE_CVE-2021-39156

Vulnerability from fkie_nvd - Published: 2021-08-24 23:15 - Updated: 2026-06-17 04:03

Severity

8.1 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Summary

Istio is an open source platform for providing a uniform way to integrate microservices, manage traffic flow across microservices, enforce policies and aggregate telemetry data. Istio 1.11.0, 1.10.3 and below, and 1.9.7 and below contain a remotely exploitable vulnerability where an HTTP request with `#fragment` in the path may bypass Istio’s URI path based authorization policies. Patches are available in Istio 1.11.1, Istio 1.10.4 and Istio 1.9.8. As a work around a Lua filter may be written to normalize the path.

References

URL	Tags
security-advisories@github.com	https://github.com/istio/istio/security/advisories/GHSA-hqxw-mm44-gc4r	Third Party Advisory
security-advisories@github.com	https://istio.io/latest/news/security/istio-security-2021-008	Vendor Advisory
af854a3a-2127-422b-91ae-364da2661108	https://github.com/istio/istio/security/advisories/GHSA-hqxw-mm44-gc4r	Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108	https://istio.io/latest/news/security/istio-security-2021-008	Vendor Advisory

Impacted products

Vendor	Product	Version
istio	istio	*
istio	istio	*
istio	istio	*

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "istio",
          "vendor": "istio",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 1.9.8"
            },
            {
              "status": "affected",
              "version": "\u003e= 1.10.0, \u003c 1.10.4"
            },
            {
              "status": "affected",
              "version": "\u003e= 1.11.0, \u003c 1.11.1"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:istio:istio:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "2FBF48C6-1E39-4692-A652-27E7DCDC81BC",
              "versionEndExcluding": "1.9.8",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:istio:istio:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "69176EED-4FB2-4CDF-A510-90C6F46C3E86",
              "versionEndExcluding": "1.10.3",
              "versionStartIncluding": "1.10.0",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:istio:istio:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "886DF572-26C9-4BC9-875F-F043D445C346",
              "versionEndExcluding": "1.11.1",
              "versionStartIncluding": "1.11.0",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Istio is an open source platform for providing a uniform way to integrate microservices, manage traffic flow across microservices, enforce policies and aggregate telemetry data. Istio 1.11.0, 1.10.3 and below, and 1.9.7 and below contain a remotely exploitable vulnerability where an HTTP request with `#fragment` in the path may bypass Istio\u2019s URI path based authorization policies. Patches are available in Istio 1.11.1, Istio 1.10.4 and Istio 1.9.8. As a work around a Lua filter may be written to normalize the path."
    },
    {
      "lang": "es",
      "value": "Istio es una plataforma de c\u00f3digo abierto que proporciona una forma uniforme de integrar microservicios, administrar el flujo de tr\u00e1fico entre microservicios, aplicar pol\u00edticas y agregar datos de telemetr\u00eda. Istio versiones 1.11.0, 1.10.3 y por debajo, y versiones 1.9.7 y por debajo, contienen una vulnerabilidad explotable de forma remota en la que una petici\u00f3n HTTP con el par\u00e1metro \"#fragment\" en la ruta puede omitir las pol\u00edticas de autorizaci\u00f3n basadas en la ruta URI de Istio. Los parches est\u00e1n disponibles en Istio versi\u00f3n 1.11.1, Istio versi\u00f3n 1.10.4 e Istio versi\u00f3n 1.9.8. Como soluci\u00f3n, puede escribirse un filtro Lua para normalizar la ruta."
    }
  ],
  "id": "CVE-2021-39156",
  "lastModified": "2026-06-17T04:03:12.743",
  "metrics": {
    "cvssMetricV2": [
      {
        "acInsufInfo": false,
        "baseSeverity": "MEDIUM",
        "cvssData": {
          "accessComplexity": "LOW",
          "accessVector": "NETWORK",
          "authentication": "NONE",
          "availabilityImpact": "NONE",
          "baseScore": 5.0,
          "confidentialityImpact": "PARTIAL",
          "integrityImpact": "NONE",
          "vectorString": "AV:N/AC:L/Au:N/C:P/I:N/A:N",
          "version": "2.0"
        },
        "exploitabilityScore": 10.0,
        "impactScore": 2.9,
        "obtainAllPrivilege": false,
        "obtainOtherPrivilege": false,
        "obtainUserPrivilege": false,
        "source": "nvd@nist.gov",
        "type": "Primary",
        "userInteractionRequired": false
      }
    ],
    "cvssMetricV31": [
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        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 8.1,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "REQUIRED",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 5.2,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      },
      {
        "cvssData": {
          "attackComplexity": "LOW",
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          "baseScore": 7.5,
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          "confidentialityImpact": "HIGH",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6,
        "source": "nvd@nist.gov",
        "type": "Primary"
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  },
  "published": "2021-08-24T23:15:10.413",
  "references": [
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://github.com/istio/istio/security/advisories/GHSA-hqxw-mm44-gc4r"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Vendor Advisory"
      ],
      "url": "https://istio.io/latest/news/security/istio-security-2021-008"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://github.com/istio/istio/security/advisories/GHSA-hqxw-mm44-gc4r"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Vendor Advisory"
      ],
      "url": "https://istio.io/latest/news/security/istio-security-2021-008"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-863"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    },
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-706"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}

CVE-2021-39156 (GCVE-0-2021-39156)

Vulnerability from cvelistv5 – Published: 2021-08-24 22:30 – Updated: 2024-08-04 01:58

Title

Fragments in Path May Lead to Authorization Policy Bypass

Summary

Severity

8.1 (High)


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

CWE

CWE-863 - Incorrect Authorization

Assigner

GitHub_M mitre root

References

2 references

URL	Tags
https://github.com/istio/istio/security/advisorie…	x_refsource_CONFIRM
https://istio.io/latest/news/security/istio-secur…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
istio	istio	Affected: < 1.9.8 Affected: >= 1.10.0, < 1.10.4 Affected: >= 1.11.0, < 1.11.1

Show details on NVD website

JSON

To clipboard

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      ],
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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.

Detection rules are retrieved from Rulezet.

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.