CVE-2021-40823

Severity CVSS v4.0:

Pending analysis

Type:

Unavailable / Other

Publication date:

13/09/2021

Last modified:

08/08/2023

Description

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.

Impact

Vector 3.x

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N CVSS v3.1 Severity and Metrics:

Base Score: 5.90 MEDIUM
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Attack Vector (AV): Network
Attack Complexity (AC): High
Privileges Required (PR): None
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): High
Integrity (I): None
Availability (A): None

Base Score 3.x

5.90

Severity 3.x

MEDIUM

Vector 2.0

AV:N/AC:M/Au:N/C:P/I:N/A:N CVSS v2.0 Severity and Metrics:

Base Score: 4.30 MEDIUM
Vector: AV:N/AC:M/Au:N/C:P/I:N/A:N

Attack Vector (AV): Network
Attack Complexity (AC): Medium
Authentication (Au): None
Confidentiality (C): Physical
Integrity (I): None
Availability (A): None