Vulnerability-Lookup

ubuntu-cve-2021-25740

Vulnerability from osv_ubuntu

Published

2021-09-20 17:15

Modified

2025-07-14 04:39

Summary

Details

A security issue was discovered with Kubernetes that could enable users to send network traffic to locations they would otherwise not have access to via a confused deputy attack.

Severity

3.1 (Low)


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

3.1 (Low)


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

N/A (UNKNOWN)


                    
                      medium

References

URL

Type

	https://ubuntu.com/security/CVE-2021-25740	REPORT
	https://www.openwall.com/lists/oss-security/2021/…	REPORT
	https://www.cve.org/CVERecord?id=CVE-2021-25740	REPORT

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {},
      "package": {
        "ecosystem": "Ubuntu:Pro:20.04:LTS",
        "name": "kubernetes",
        "purl": "pkg:deb/ubuntu/kubernetes@1.0?arch=source\u0026distro=esm-apps/focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.0"
      ]
    },
    {
      "ecosystem_specific": {},
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "kubernetes",
        "purl": "pkg:deb/ubuntu/kubernetes@1.0?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.0"
      ]
    },
    {
      "ecosystem_specific": {},
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "kubernetes",
        "purl": "pkg:deb/ubuntu/kubernetes@1.0?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.0"
      ]
    }
  ],
  "aliases": [],
  "details": "A security issue was discovered with Kubernetes that could enable users to send network traffic to locations they would otherwise not have access to via a confused deputy attack.",
  "id": "UBUNTU-CVE-2021-25740",
  "modified": "2025-07-14T04:39:34Z",
  "published": "2021-09-20T17:15:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2021-25740"
    },
    {
      "type": "REPORT",
      "url": "https://www.openwall.com/lists/oss-security/2021/07/14/1"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2021-25740"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2021-25740"
  ],
  "withdrawn": "2025-08-28T17:00:31Z"
}

CVE-2021-25740 (GCVE-0-2021-25740)

Vulnerability from cvelistv5 – Published: 2021-09-20 17:05 – Updated: 2026-06-01 21:45

Title

Holes in EndpointSlice Validation Enable Host Network Hijack

Summary

A security issue was discovered with Kubernetes that could enable users to send network traffic to locations they would otherwise not have access to via a confused deputy attack.

Severity

3.1 (Low)


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

CWE

CWE-441 - Unintended Proxy or Intermediary

Assigner

kubernetes

References

4 references

URL	Tags
https://kubernetes.io/blog/2026/05/26/reconciling…	x_refsource_MISC
https://groups.google.com/g/kubernetes-security-a…	x_refsource_MISC
https://github.com/kubernetes/kubernetes/issues/103675	x_refsource_MISC
https://security.netapp.com/advisory/ntap-2021101…	x_refsource_CONFIRM

Impacted products

1 product

Vendor	Product	Version
Kubernetes	Kubernetes	Affected: 0 , < * (semver)

Date Public

2021-07-14 00:00

Credits

Rob Scott

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-03T20:11:27.960Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://groups.google.com/g/kubernetes-security-announce/c/WYE9ptrhSLE"
          },
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://github.com/kubernetes/kubernetes/issues/103675"
          },
          {
            "tags": [
              "x_refsource_CONFIRM",
              "x_transferred"
            ],
            "url": "https://security.netapp.com/advisory/ntap-20211014-0001/"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "Kubernetes",
          "vendor": "Kubernetes",
          "versions": [
            {
              "lessThan": "*",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "value": "Rob Scott"
        }
      ],
      "datePublic": "2021-07-14T00:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "A security issue was discovered with Kubernetes that could enable users to send network traffic to locations they would otherwise not have access to via a confused deputy attack."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 3.1,
            "baseSeverity": "LOW",
            "confidentialityImpact": "LOW",
            "integrityImpact": "NONE",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-441",
              "description": "CWE-441 Unintended Proxy or Intermediary",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-06-01T21:45:55.645Z",
        "orgId": "a6081bf6-c852-4425-ad4f-a67919267565",
        "shortName": "kubernetes"
      },
      "references": [
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://kubernetes.io/blog/2026/05/26/reconciling-unfixed-kubernetes-cves/"
        },
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://groups.google.com/g/kubernetes-security-announce/c/WYE9ptrhSLE"
        },
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/kubernetes/kubernetes/issues/103675"
        },
        {
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://security.netapp.com/advisory/ntap-20211014-0001/"
        }
      ],
      "source": {
        "defect": [
          "https://github.com/kubernetes/kubernetes/issues/103675"
        ],
        "discovery": "EXTERNAL"
      },
      "title": "Holes in EndpointSlice Validation Enable Host Network Hijack",
      "x_generator": {
        "engine": "Vulnogram 0.0.9"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a6081bf6-c852-4425-ad4f-a67919267565",
    "assignerShortName": "kubernetes",
    "cveId": "CVE-2021-25740",
    "datePublished": "2021-09-20T17:05:18.065Z",
    "dateReserved": "2021-01-21T00:00:00.000Z",
    "dateUpdated": "2026-06-01T21:45:55.645Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.

Action not permitted

ubuntu-cve-2021-25740

Vulnerability from osv_ubuntu

CVE-2021-25740 (GCVE-0-2021-25740)

Tags

Sightings

Nomenclature