GHSA-22P3-QRH9-CX32

Vulnerability from github – Published: 2022-06-29 21:51 – Updated: 2024-09-30 20:29
VLAI?
Summary
URL previews of unusual or maliciously-crafted pages can crash Synapse media repositories or Synapse monoliths
Details

Impact

URL previews of some web pages can exhaust the available stack space for the Synapse process due to unbounded recursion. This is sometimes recoverable and leads to an error for the request causing the problem, but in other cases the Synapse process may crash altogether.

It is possible to exploit this maliciously, either by malicious users on the homeserver, or by remote users sending URLs that a local user's client may automatically request a URL preview for. Remote users are not able to exploit this directly, because the URL preview endpoint is authenticated.

Am I affected?

  • deployments with url_preview_enabled: false set in configuration are not affected.
  • deployments with url_preview_enabled: true set in configuration are affected.
  • deployments with no configuration value set for url_preview_enabled are not affected, because the default is false.

Patches

Administrators of homeservers with URL previews enabled are advised to upgrade to v1.61.1 or higher.

Workarounds

  • URL previews can be disabled in the configuration file by setting url_preview_enabled: false.
  • Deployments using workers can choose to offload URL previews to one or more dedicated worker(s), ensuring that a process crash does not disrupt other functionality of Synapse.

For more information

If you have any questions or comments about this advisory, e-mail us at security@matrix.org.

Severity ?
6.5 (Medium)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
7.1 (High)
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
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{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "matrix-synapse"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.61.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2022-31052"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-674"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2022-06-29T21:51:23Z",
    "nvd_published_at": "2022-06-28T17:15:00Z",
    "severity": "HIGH"
  },
  "details": "### Impact\n\nURL previews of some web pages can exhaust the available stack space for the Synapse process due to unbounded recursion.\nThis is sometimes recoverable and leads to an error for the request causing the problem, but in other cases the Synapse process may crash altogether.\n\nIt is possible to exploit this maliciously, either by malicious users on the homeserver, or by remote users sending URLs that a local user\u0027s client may automatically request a URL preview for.\nRemote users are not able to exploit this directly, because [the URL preview endpoint is authenticated](https://spec.matrix.org/v1.2/client-server-api/#get_matrixmediav3preview_url).\n\n### Am I affected?\n\n* deployments with `url_preview_enabled: false` set in configuration are not affected.\n* deployments with `url_preview_enabled: true` set in configuration **are** affected.\n* deployments with no configuration value set for `url_preview_enabled` are not affected, because the default is `false`.\n\n### Patches\n\nAdministrators of homeservers with URL previews enabled are advised to upgrade to v1.61.1 or higher.\n\n### Workarounds\n\n* URL previews can be disabled in the configuration file by setting `url_preview_enabled: false`.\n* Deployments using workers can choose to offload URL previews to one or more dedicated worker(s), ensuring that a process crash does not disrupt other functionality of Synapse.\n\n### For more information\n\nIf you have any questions or comments about this advisory, e-mail us at [security@matrix.org](mailto:security@matrix.org).\n",
  "id": "GHSA-22p3-qrh9-cx32",
  "modified": "2024-09-30T20:29:11Z",
  "published": "2022-06-29T21:51:23Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/matrix-org/synapse/security/advisories/GHSA-22p3-qrh9-cx32"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2022-31052"
    },
    {
      "type": "WEB",
      "url": "https://github.com/matrix-org/synapse/commit/fa1308061802ac7b7d20e954ba7372c5ac292333"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/matrix-org/synapse"
    },
    {
      "type": "WEB",
      "url": "https://github.com/pypa/advisory-database/tree/main/vulns/matrix-synapse/PYSEC-2022-224.yaml"
    },
    {
      "type": "WEB",
      "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/7EARKKJZ2W7WUITFDT4EG4NVATFYJQHF"
    },
    {
      "type": "WEB",
      "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/QGSDQ4YAITCUACAB7SXQZDJIU3IQ4CJD"
    },
    {
      "type": "WEB",
      "url": "https://spec.matrix.org/v1.2/client-server-api/#get_matrixmediav3preview_url"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "URL previews of unusual or maliciously-crafted pages can crash Synapse media repositories or Synapse monoliths"
}


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Sightings

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  • 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.