Vulnerability-Lookup

UBUNTU-CVE-2021-21392 (CVE-2021-21392)

Vulnerability from osv_ubuntu – Published: 2021-04-12 22:15 – Updated: 2025-10-24 04:50 – Source website

Details

Synapse is a Matrix reference homeserver written in python (pypi package matrix-synapse). Matrix is an ecosystem for open federated Instant Messaging and VoIP. In Synapse before version 1.28.0 requests to user provided domains were not restricted to external IP addresses when transitional IPv6 addresses were used. Outbound requests to federation, identity servers, when calculating the key validity for third-party invite events, sending push notifications, and generating URL previews are affected. This could cause Synapse to make requests to internal infrastructure on dual-stack networks. See referenced GitHub security advisory for details and workarounds.

Severity

6.3 (Medium)


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

6.3 (Medium)


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

N/A (UNKNOWN)


                    
                      medium

References

URL

Type

	https://ubuntu.com/security/CVE-2021-21392	REPORT
	https://github.com/matrix-org/synapse/security/ad…	REPORT
	https://github.com/matrix-org/synapse/pull/9240	REPORT
	https://pypi.org/project/matrix-synapse/	REPORT
	https://www.cve.org/CVERecord?id=CVE-2021-21392	REPORT

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "matrix-synapse",
            "binary_version": "0.24.0+dfsg-1ubuntu0.1~esm4"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:18.04:LTS",
        "name": "matrix-synapse",
        "purl": "pkg:deb/ubuntu/matrix-synapse@0.24.0+dfsg-1ubuntu0.1~esm4?arch=source\u0026distro=esm-apps/bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.19.2+dfsg-6",
        "0.24.0+dfsg-1",
        "0.24.0+dfsg-1ubuntu0.1~esm1",
        "0.24.0+dfsg-1ubuntu0.1~esm4"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "matrix-synapse",
            "binary_version": "1.11.0-1ubuntu0.1~esm2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:20.04:LTS",
        "name": "matrix-synapse",
        "purl": "pkg:deb/ubuntu/matrix-synapse@1.11.0-1ubuntu0.1~esm2?arch=source\u0026distro=esm-apps/focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.3.0-1",
        "1.4.0-1",
        "1.5.0-1",
        "1.5.1-1",
        "1.6.0-1",
        "1.6.1-1",
        "1.7.0-2",
        "1.7.1-1",
        "1.7.2-1",
        "1.7.3-1",
        "1.8.0-1",
        "1.9.0-1",
        "1.9.1-1",
        "1.10.0-1",
        "1.10.0-2",
        "1.11.0-1",
        "1.11.0-1ubuntu0.1~esm2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "matrix-synapse",
            "binary_version": "1.53.0-1ubuntu0.1~esm2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:22.04:LTS",
        "name": "matrix-synapse",
        "purl": "pkg:deb/ubuntu/matrix-synapse@1.53.0-1ubuntu0.1~esm2?arch=source\u0026distro=esm-apps/jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.39.0-1",
        "1.47.0-2",
        "1.47.1-1",
        "1.48.0-1",
        "1.49.0-1",
        "1.49.2-1",
        "1.50.1-1",
        "1.50.2-1",
        "1.51.0-1",
        "1.52.0-1",
        "1.53.0-1",
        "1.53.0-1ubuntu0.1~esm2"
      ]
    }
  ],
  "aliases": [],
  "details": "Synapse is a Matrix reference homeserver written in python (pypi package matrix-synapse). Matrix is an ecosystem for open federated Instant Messaging and VoIP. In Synapse before version 1.28.0 requests to user provided domains were not restricted to external IP addresses when transitional IPv6 addresses were used. Outbound requests to federation, identity servers, when calculating the key validity for third-party invite events, sending push notifications, and generating URL previews are affected. This could cause Synapse to make requests to internal infrastructure on dual-stack networks. See referenced GitHub security advisory for details and workarounds.",
  "id": "UBUNTU-CVE-2021-21392",
  "modified": "2025-10-24T04:50:06Z",
  "published": "2021-04-12T22:15:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2021-21392"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/matrix-org/synapse/security/advisories/GHSA-5wrh-4jwv-5w78"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/matrix-org/synapse/pull/9240"
    },
    {
      "type": "REPORT",
      "url": "https://pypi.org/project/matrix-synapse/"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2021-21392"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:H/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:H/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2021-21392"
  ]
}

CVE-2021-21392 (GCVE-0-2021-21392)

Vulnerability from cvelistv5 – Published: 2021-04-12 21:50 – Updated: 2024-08-03 18:09

Title

Open redirect via transitional IPv6 addresses on dual-stack networks

Summary

Severity

6.3 (Medium)


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

CWE

CWE-601 - URL Redirection to Untrusted Site ('Open Redirect')

Assigner

GitHub_M CNA under the mitre root

CNA scorecard C 72/100 over 7760 records in the last 180 days details

References

4 references

URL	Tags
https://pypi.org/project/matrix-synapse/	x_refsource_MISC
https://github.com/matrix-org/synapse/security/ad…	x_refsource_CONFIRM
https://github.com/matrix-org/synapse/pull/9240	x_refsource_MISC
https://lists.fedoraproject.org/archives/list/pac…	vendor-advisoryx_refsource_FEDORA

Impacted products

1 product

Vendor	Product	Version
matrix-org	synapse	Affected: < 1.28.0

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-03T18:09:15.930Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
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        "references": [
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              "x_transferred"
            ],
            "url": "https://pypi.org/project/matrix-synapse/"
          },
          {
            "tags": [
              "x_refsource_CONFIRM",
              "x_transferred"
            ],
            "url": "https://github.com/matrix-org/synapse/security/advisories/GHSA-5wrh-4jwv-5w78"
          },
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://github.com/matrix-org/synapse/pull/9240"
          },
          {
            "name": "FEDORA-2021-a627cfd31e",
            "tags": [
              "vendor-advisory",
              "x_refsource_FEDORA",
              "x_transferred"
            ],
            "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TNNAJOZNMVMXM6AS7RFFKB4QLUJ4IFEY/"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "synapse",
          "vendor": "matrix-org",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 1.28.0"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Synapse is a Matrix reference homeserver written in python (pypi package matrix-synapse). Matrix is an ecosystem for open federated Instant Messaging and VoIP. In Synapse before version 1.28.0 requests to user provided domains were not restricted to external IP addresses when transitional IPv6 addresses were used. Outbound requests to federation, identity servers, when calculating the key validity for third-party invite events, sending push notifications, and generating URL previews are affected. This could cause Synapse to make requests to internal infrastructure on dual-stack networks. See referenced GitHub security advisory for details and workarounds."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 6.3,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "LOW",
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:H/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-601",
              "description": "CWE-601 URL Redirection to Untrusted Site (\u0027Open Redirect\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2021-08-02T02:06:34.000Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://pypi.org/project/matrix-synapse/"
        },
        {
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/matrix-org/synapse/security/advisories/GHSA-5wrh-4jwv-5w78"
        },
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/matrix-org/synapse/pull/9240"
        },
        {
          "name": "FEDORA-2021-a627cfd31e",
          "tags": [
            "vendor-advisory",
            "x_refsource_FEDORA"
          ],
          "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TNNAJOZNMVMXM6AS7RFFKB4QLUJ4IFEY/"
        }
      ],
      "source": {
        "advisory": "GHSA-5wrh-4jwv-5w78",
        "discovery": "UNKNOWN"
      },
      "title": "Open redirect via transitional IPv6 addresses on dual-stack networks",
      "x_legacyV4Record": {
        "CVE_data_meta": {
          "ASSIGNER": "security-advisories@github.com",
          "ID": "CVE-2021-21392",
          "STATE": "PUBLIC",
          "TITLE": "Open redirect via transitional IPv6 addresses on dual-stack networks"
        },
        "affects": {
          "vendor": {
            "vendor_data": [
              {
                "product": {
                  "product_data": [
                    {
                      "product_name": "synapse",
                      "version": {
                        "version_data": [
                          {
                            "version_value": "\u003c 1.28.0"
                          }
                        ]
                      }
                    }
                  ]
                },
                "vendor_name": "matrix-org"
              }
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        "data_version": "4.0",
        "description": {
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            "privilegesRequired": "LOW",
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            "userInteraction": "REQUIRED",
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            "version": "3.1"
          }
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            {
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                {
                  "lang": "eng",
                  "value": "CWE-601 URL Redirection to Untrusted Site (\u0027Open Redirect\u0027)"
                }
              ]
            }
          ]
        },
        "references": {
          "reference_data": [
            {
              "name": "https://pypi.org/project/matrix-synapse/",
              "refsource": "MISC",
              "url": "https://pypi.org/project/matrix-synapse/"
            },
            {
              "name": "https://github.com/matrix-org/synapse/security/advisories/GHSA-5wrh-4jwv-5w78",
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    "datePublished": "2021-04-12T21:50:14.000Z",
    "dateReserved": "2020-12-22T00:00:00.000Z",
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    "state": "PUBLISHED"
  },
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  "dataVersion": "5.1"
}

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.

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UBUNTU-CVE-2021-21392 (CVE-2021-21392)

CVE-2021-21392 (GCVE-0-2021-21392)

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