ghsa-w9mh-5x8j-9754
Vulnerability from github
Published
2024-07-05 20:06
Modified
2024-07-05 21:37
Severity ?
4.3 (Medium) - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Summary
Malicious Matrix homeserver can leak truncated message content of messages it shouldn't have access to
Details

Impact

The fix for GHSA-wm4w-7h2q-3pf7 / CVE-2024-32000 included in matrix-appservice-irc 2.0.0 relied on the Matrix homeserver-provided timestamp to determine whether a user has access to the event they're replying to when determining whether or not to include a truncated version of the original event in the IRC message. Since this value is controlled by external entities, a malicious Matrix homeserver joined to a room in which a matrix-appservice-irc bridge instance (before version 2.0.1) is present can fabricate the timestamp with the intent of tricking the bridge into leaking room messages the homeserver should not have access to.

Patches

matrix-appservice-irc 2.0.1 drops the reliance on origin_server_ts when determining whether or not an event should be visible to a user, instead tracking the event timestamps internally.

Workarounds

It's possible to limit the amount of information leaked by setting a reply template that doesn't contain the original message. See these lines in the configuration file.

References

  • Patch: https://github.com/matrix-org/matrix-appservice-irc/pull/1804

For more information

If you have any questions or comments about this advisory, please email us at security at matrix.org.

Show details on source website

To clipboard 

{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 2.0.0"
      },
      "package": {
        "ecosystem": "npm",
        "name": "matrix-appservice-irc"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.0.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2024-39691"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-280",
      "CWE-755"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2024-07-05T20:06:06Z",
    "nvd_published_at": "2024-07-05T19:15:10Z",
    "severity": "MODERATE"
  },
  "details": "### Impact\n\nThe fix for GHSA-wm4w-7h2q-3pf7 / [CVE-2024-32000](https://www.cve.org/CVERecord?id=CVE-2024-32000) included in matrix-appservice-irc 2.0.0 relied on the Matrix homeserver-provided timestamp to determine whether a user has access to the event they\u0027re replying to when determining whether or not to include a truncated version of the original event in the IRC message. Since this value is controlled by external entities, a malicious Matrix homeserver joined to a room in which a matrix-appservice-irc bridge instance (before version 2.0.1) is present can fabricate the timestamp with the intent of tricking the bridge into leaking room messages the homeserver should not have access to.\n\n### Patches\n\nmatrix-appservice-irc 2.0.1 [drops the reliance](https://github.com/matrix-org/matrix-appservice-irc/pull/1804) on `origin_server_ts` when determining whether or not an event should be visible to a user, instead tracking the event timestamps internally.\n\n### Workarounds\n\nIt\u0027s possible to limit the amount of information leaked by setting a reply template that doesn\u0027t contain the original message. See [these lines](https://github.com/matrix-org/matrix-appservice-irc/blob/d5d67d1d3ea3f0f6962a0af2cc57b56af3ad2129/config.sample.yaml#L601-L604) in the configuration file.\n\n### References\n\n- Patch: https://github.com/matrix-org/matrix-appservice-irc/pull/1804\n\n### For more information\n\nIf you have any questions or comments about this advisory, please email us at [security at matrix.org](mailto:security@matrix.org).",
  "id": "GHSA-w9mh-5x8j-9754",
  "modified": "2024-07-05T21:37:31Z",
  "published": "2024-07-05T20:06:06Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/matrix-org/matrix-appservice-irc/security/advisories/GHSA-w9mh-5x8j-9754"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-39691"
    },
    {
      "type": "WEB",
      "url": "https://github.com/matrix-org/matrix-appservice-irc/pull/1804"
    },
    {
      "type": "WEB",
      "url": "https://github.com/matrix-org/matrix-appservice-irc/commit/1835e047f269001054be4c68867797aa12372a0f"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/matrix-org/matrix-appservice-irc"
    },
    {
      "type": "WEB",
      "url": "https://github.com/matrix-org/matrix-appservice-irc/blob/d5d67d1d3ea3f0f6962a0af2cc57b56af3ad2129/config.sample.yaml#L601-L604"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Malicious Matrix homeserver can leak truncated message content of messages it shouldn\u0027t have access to"
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.