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FKIE_CVE-2023-45129

Vulnerability from fkie_nvd - Published: 2023-10-10 18:15 - Updated: 2026-06-17 06:28
Severity
4.9 (Medium) - CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
4.9 (Medium) - CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
Summary
Synapse is an open-source Matrix homeserver written and maintained by the Matrix.org Foundation. Prior to version 1.94.0, a malicious server ACL event can impact performance temporarily or permanently leading to a persistent denial of service. Homeservers running on a closed federation (which presumably do not need to use server ACLs) are not affected. Server administrators are advised to upgrade to Synapse 1.94.0 or later. As a workaround, rooms with malicious server ACL events can be purged and blocked using the admin API.
References
security-advisories@github.comhttps://github.com/matrix-org/synapse/pull/16360Patch, Vendor Advisory
security-advisories@github.comhttps://github.com/matrix-org/synapse/security/advisories/GHSA-5chr-wjw5-3gq4Vendor Advisory
security-advisories@github.comhttps://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/KEVRB4MG5UXQ5RLZHSUJXM5GWEBYYS5B/Mailing List
security-advisories@github.comhttps://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/N6P4QULVUE254WI7XF2LWWOGHCYVFXFY/
security-advisories@github.comhttps://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/WRO4MPQ6HOXIUZM6RJP6VTCTMV7RD2T3/Mailing List
security-advisories@github.comhttps://matrix-org.github.io/synapse/latest/admin_api/rooms.html#version-2-new-versionRelease Notes
security-advisories@github.comhttps://security.gentoo.org/glsa/202401-12
af854a3a-2127-422b-91ae-364da2661108https://github.com/matrix-org/synapse/pull/16360Patch, Vendor Advisory
af854a3a-2127-422b-91ae-364da2661108https://github.com/matrix-org/synapse/security/advisories/GHSA-5chr-wjw5-3gq4Vendor Advisory
af854a3a-2127-422b-91ae-364da2661108https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/KEVRB4MG5UXQ5RLZHSUJXM5GWEBYYS5B/Mailing List
af854a3a-2127-422b-91ae-364da2661108https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/N6P4QULVUE254WI7XF2LWWOGHCYVFXFY/
af854a3a-2127-422b-91ae-364da2661108https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/WRO4MPQ6HOXIUZM6RJP6VTCTMV7RD2T3/Mailing List
af854a3a-2127-422b-91ae-364da2661108https://matrix-org.github.io/synapse/latest/admin_api/rooms.html#version-2-new-versionRelease Notes
af854a3a-2127-422b-91ae-364da2661108https://security.gentoo.org/glsa/202401-12
Impacted products
Vendor Product Version
matrix synapse *
fedoraproject fedora 37
fedoraproject fedora 38
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "synapse",
          "vendor": "matrix-org",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 1.94.0"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:matrix:synapse:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "3493E32E-7CAA-4B40-9763-DA34F4209328",
              "versionEndExcluding": "1.94.0",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    },
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:fedoraproject:fedora:37:*:*:*:*:*:*:*",
              "matchCriteriaId": "E30D0E6F-4AE8-4284-8716-991DFA48CC5D",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:fedoraproject:fedora:38:*:*:*:*:*:*:*",
              "matchCriteriaId": "CC559B26-5DFC-4B7A-A27C-B77DE755DFF9",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Synapse is an open-source Matrix homeserver written and maintained by the Matrix.org Foundation. Prior to version 1.94.0, a malicious server ACL event can impact performance temporarily or permanently leading to a persistent denial of service. Homeservers running on a closed federation (which presumably do not need to use server ACLs) are not affected. Server administrators are advised to upgrade to Synapse 1.94.0 or later. As a workaround, rooms with malicious server ACL events can be purged and blocked using the admin API."
    },
    {
      "lang": "es",
      "value": "Synapse es un servidor dom\u00e9stico Matrix de c\u00f3digo abierto escrito y mantenido por la Fundaci\u00f3n Matrix.org. Antes de la versi\u00f3n 1.94.0, un evento de ACL de servidor malicioso pod\u00eda afectar el rendimiento de forma temporal o permanente y provocar una denegaci\u00f3n de servicio persistente. Los servidores dom\u00e9sticos que se ejecutan en una federaci\u00f3n cerrada (que presumiblemente no necesitan usar ACL de servidor) no se ven afectados. Se recomienda a los administradores del servidor que actualicen a Synapse 1.94.0 o posterior. Como workaround, las salas con eventos de ACL de servidor maliciosos se pueden eliminar y bloquear mediante la API de administraci\u00f3n."
    }
  ],
  "id": "CVE-2023-45129",
  "lastModified": "2026-06-17T06:28:16.450",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 4.9,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "HIGH",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.2,
        "impactScore": 3.6,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      },
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 4.9,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "HIGH",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.2,
        "impactScore": 3.6,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ]
  },
  "published": "2023-10-10T18:15:19.093",
  "references": [
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      "tags": [
        "Patch",
        "Vendor Advisory"
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      "url": "https://github.com/matrix-org/synapse/pull/16360"
    },
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    },
    {
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      "tags": [
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    },
    {
      "source": "security-advisories@github.com",
      "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/N6P4QULVUE254WI7XF2LWWOGHCYVFXFY/"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Mailing List"
      ],
      "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/WRO4MPQ6HOXIUZM6RJP6VTCTMV7RD2T3/"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Release Notes"
      ],
      "url": "https://matrix-org.github.io/synapse/latest/admin_api/rooms.html#version-2-new-version"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://security.gentoo.org/glsa/202401-12"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
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        "Vendor Advisory"
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      "url": "https://github.com/matrix-org/synapse/pull/16360"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
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      ],
      "url": "https://github.com/matrix-org/synapse/security/advisories/GHSA-5chr-wjw5-3gq4"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Mailing List"
      ],
      "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/KEVRB4MG5UXQ5RLZHSUJXM5GWEBYYS5B/"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/N6P4QULVUE254WI7XF2LWWOGHCYVFXFY/"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Mailing List"
      ],
      "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/WRO4MPQ6HOXIUZM6RJP6VTCTMV7RD2T3/"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
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      ],
      "url": "https://matrix-org.github.io/synapse/latest/admin_api/rooms.html#version-2-new-version"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "url": "https://security.gentoo.org/glsa/202401-12"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-770"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    },
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-770"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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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.
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