ghsa-4822-jvwx-w47h
Vulnerability from github
Published
2022-04-01 18:16
Modified
2022-11-28 16:18
Severity ?
5.3 (Medium) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Summary
Uncontrolled Resource Consumption in Matrix Synapse
Details

Impact

Synapse before 1.52.0 with URL preview functionality enabled will attempt to generate URL previews for media stream URLs without properly limiting connection time. Connections will only be terminated after max_spider_size (default: 10M) bytes have been downloaded, which can in some cases lead to long-lived connections towards the streaming media server (for instance, Icecast).

This can cause excessive traffic and connections toward such servers if their stream URL is, for example, posted to a large room with many Synapse instances with URL preview enabled.

Patches

1.52.0 implements a timeout mechanism which will terminate URL preview connections after 30 seconds. Since generating URL previews for media streams is not supported and always fails, 1.53.0 additionally implements an allow list for content types for which Synapse will even attempt to generate a URL preview.

We recommend upgrading to 1.53.0 to fully resolve the issue.

Workarounds

Turn off URL preview functionality by setting url_preview_enabled: false in the Synapse configuration file.

References

  • Patch (timeout): https://github.com/matrix-org/synapse/pull/11784
  • Patch (content type allow list): https://github.com/matrix-org/synapse/pull/11936

For more information

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

Show details on source website

To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "matrix-synapse"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.53.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2022-41952"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-400",
      "CWE-772"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2022-04-01T18:16:42Z",
    "nvd_published_at": "2022-11-22T16:15:00Z",
    "severity": "MODERATE"
  },
  "details": "### Impact\n\nSynapse before 1.52.0 with URL preview functionality enabled will attempt to generate URL previews for media stream URLs without properly limiting connection time. Connections will only be terminated after `max_spider_size` (default: 10M) bytes have been downloaded, which can in some cases lead to long-lived connections towards the streaming media server (for instance, Icecast).\n\nThis can cause excessive traffic and connections toward such servers if their stream URL is, for example, posted to a large room with many Synapse instances with URL preview enabled.\n\n### Patches\n1.52.0 implements a timeout mechanism which will terminate URL preview connections after 30 seconds. Since generating URL previews for media streams is not supported and always fails, 1.53.0 additionally implements an allow list for content types for which Synapse will even attempt to generate a URL preview.\n\nWe recommend upgrading to 1.53.0 to fully resolve the issue.\n\n### Workarounds\nTurn off URL preview functionality by setting `url_preview_enabled: false` in the Synapse configuration file.\n\n### References\n- Patch (timeout): https://github.com/matrix-org/synapse/pull/11784\n- Patch (content type allow list): https://github.com/matrix-org/synapse/pull/11936\n\n### For more information\nIf you have any questions or comments about this advisory, e-mail us at security@matrix.org.\n",
  "id": "GHSA-4822-jvwx-w47h",
  "modified": "2022-11-28T16:18:30Z",
  "published": "2022-04-01T18:16:42Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/matrix-org/synapse/security/advisories/GHSA-4822-jvwx-w47h"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2022-41952"
    },
    {
      "type": "WEB",
      "url": "https://github.com/matrix-org/synapse/pull/11784"
    },
    {
      "type": "WEB",
      "url": "https://github.com/matrix-org/synapse/pull/11936"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/matrix-org/synapse"
    },
    {
      "type": "WEB",
      "url": "https://github.com/matrix-org/synapse/releases/tag/v1.52.0"
    },
    {
      "type": "WEB",
      "url": "https://github.com/matrix-org/synapse/releases/tag/v1.53.0"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Uncontrolled Resource Consumption in Matrix Synapse"
}


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