CVE Vulnerabilities

CVE-2021-40823

Authentication Bypass by Spoofing

Published: Sep 13, 2021 | Modified: Aug 08, 2023
CVSS 3.x
5.9
MEDIUM
Source:
NVD
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
CVSS 2.x
4.3 MEDIUM
AV:N/AC:M/Au:N/C:P/I:N/A:N
RedHat/V2
RedHat/V3
Ubuntu
MEDIUM

A logic error in the room key sharing functionality of matrix-js-sdk (aka Matrix Javascript SDK) before 12.4.1 allows a malicious Matrix homeserver present in an encrypted room to steal room encryption keys (via crafted Matrix protocol messages) that were originally sent by affected Matrix clients participating in that room. This allows the homeserver to decrypt end-to-end encrypted messages sent by affected clients.

Weakness

This attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks.

Affected Software

Name Vendor Start Version End Version
Javascript_sdk Matrix * 12.4.1 (excluding)
Element-web Ubuntu trusty *
Element-web Ubuntu xenial *
Node-matrix-js-sdk Ubuntu hirsute *
Node-matrix-js-sdk Ubuntu impish *
Node-matrix-js-sdk Ubuntu kinetic *
Node-matrix-js-sdk Ubuntu lunar *
Node-matrix-js-sdk Ubuntu mantic *
Node-matrix-js-sdk Ubuntu trusty *
Node-matrix-js-sdk Ubuntu xenial *

References