6.5
MEDIUM CVSS 3.1
CVE-2021-32659
Automatic room upgrade handling can be used maliciously to bridge a room non-consentually
Description

Matrix-appservice-bridge is the bridging service for the Matrix communication program's application services. In versions 2.6.0 and earlier, 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 malicious admin of a bridged room can repoint the traffic to a different room without the new room being aware. Versions 2.6.1 and greater are patched. As a workaround, disabling the automatic room upgrade handling can be done by removing the `roomUpgradeOpts` key from the `Bridge` class options.

INFO

Published Date :

June 16, 2021, 7:15 p.m.

Last Modified :

Nov. 21, 2024, 6:07 a.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2021-32659 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Matrix matrix-appservice-bridge
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 2.0 LOW [email protected]
CVSS 3.1 MEDIUM [email protected]
CVSS 3.1 MEDIUM [email protected]
References to Advisories, Solutions, and Tools
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2021-32659 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2021-32659 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2021-32659 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by af854a3a-2127-422b-91ae-364da2661108

    Nov. 21, 2024

    Action Type Old Value New Value
    Added Reference https://github.com/matrix-org/matrix-appservice-bridge/commit/b69e745584a34fcfd858df33e4631e420da07b9f
    Added Reference https://github.com/matrix-org/matrix-appservice-bridge/releases/tag/2.6.1
    Added Reference https://github.com/matrix-org/matrix-appservice-bridge/security/advisories/GHSA-35g4-qx3c-vjhx
  • CVE Modified by [email protected]

    May. 14, 2024

    Action Type Old Value New Value
  • Initial Analysis by [email protected]

    Jul. 09, 2021

    Action Type Old Value New Value
    Added CVSS V2 NIST (AV:N/AC:M/Au:S/C:N/I:P/A:N)
    Added CVSS V3.1 NIST AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N
    Changed Reference Type https://github.com/matrix-org/matrix-appservice-bridge/commit/b69e745584a34fcfd858df33e4631e420da07b9f No Types Assigned https://github.com/matrix-org/matrix-appservice-bridge/commit/b69e745584a34fcfd858df33e4631e420da07b9f Patch, Third Party Advisory
    Changed Reference Type https://github.com/matrix-org/matrix-appservice-bridge/releases/tag/2.6.1 No Types Assigned https://github.com/matrix-org/matrix-appservice-bridge/releases/tag/2.6.1 Patch, Third Party Advisory
    Changed Reference Type https://github.com/matrix-org/matrix-appservice-bridge/security/advisories/GHSA-35g4-qx3c-vjhx No Types Assigned https://github.com/matrix-org/matrix-appservice-bridge/security/advisories/GHSA-35g4-qx3c-vjhx Mitigation, Third Party Advisory
    Added CPE Configuration OR *cpe:2.3:a:matrix:matrix-appservice-bridge:*:*:*:*:*:node.js:*:* versions up to (excluding) 2.6.1
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
Vulnerability Scoring Details
Base CVSS Score: 6.5
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact
Base CVSS Score: 3.5
Access Vector
Access Complexity
Authentication
Confidentiality Impact
Integrity Impact
Availability Impact
Exploit Prediction

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.

0.27 }} -0.25%

score

0.47353

percentile