GHSA-35g4-qx3c-vjhx

Source

https://github.com/advisories/GHSA-35g4-qx3c-vjhx

Import Source

https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2021/06/GHSA-35g4-qx3c-vjhx/GHSA-35g4-qx3c-vjhx.json

JSON Data

https://api.osv.dev/v1/vulns/GHSA-35g4-qx3c-vjhx

Aliases

CVE-2021-32659

Published

2021-06-21T17:09:22Z

Modified

2026-07-08T06:29:05Z

Severity

6.5 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N CVSS Calculator

Summary

Automatic room upgrade handling can be used maliciously to bridge a room non-consentually

Details

Impact

If a bridge has room upgrade handling turned on in the configuration (the roomUpgradeOpts key when instantiating a new Bridge instance.), any m.room.tombstone event it encounters will be used to unbridge the current room and bridge into the target room. However, the target room m.room.create event is not checked to verify if the predecessor field contains the previous room. This means that any mailcious admin of a bridged room can repoint the traffic to a different room without the new room being aware.

Patches

Versions 2.6.1 and greater are patched.

Workarounds

Disabling the automatic room upgrade handling can be done by removing the roomUpgradeOpts key from the Bridge class options.

References

The issue is patched by https://github.com/matrix-org/matrix-appservice-bridge/pull/330

For more information]

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

Database specific

{
    "cwe_ids":  [
        "CWE-306"
    ],
    "github_reviewed":  true,
    "github_reviewed_at":  "2021-06-16T20:08:37Z",
    "nvd_published_at":  "2021-06-16T19:15:00Z",
    "severity":  "MODERATE"
}

References

Affected packages

npm / matrix-appservice-bridge

Package

Name: matrix-appservice-bridge; View open source insights on deps.dev
Purl: pkg:npm/matrix-appservice-bridge

Affected ranges

Type: SEMVER
Events: Introduced

0 Unknown introduced version / All previous versions are affected

Fixed

2.6.1

Database specific

source

"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2021/06/GHSA-35g4-qx3c-vjhx/GHSA-35g4-qx3c-vjhx.json"