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CVE-2021-40823

Published: Sep 13, 2021Updated: Nov 21, 2024 Sources: CVE List NVD GHSACWE-290
NVD MITRE
5.9CVSSMEDIUM
EPSS Score
0.6%
Top 54.1%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available

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.

CVSS Vector Breakdown

AV:NAC:HPR:NUI:NS:UC:HI:NA:N
Exploitability
AV:NAttack Vector
Network
AC:HAttack Complexity
High
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:HConfidentiality
High
I:NIntegrity
None
A:NAvailability
None
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Weaknesses

CWE-290

Affected Products

javascript sdkmatrix
Mixed
Communications / messaging-chat
n/an/a
matrix-js-sdknpmOSS Libraries
matrixoss-projectGBCommunicationsaka synapse, matrix irc bridge, javascript sdk
npmpackage-ecosystemOSS Libraries

Attack Graph

Products CVE Techniques Tactics

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Exploitability

Official Patch Available

MITRE ATT&CK

1 technique
Initial Access
View detailed technique mapping

References

https://github.com/matrix-org/matrix-js-sdk/releases/tag/v12.4.1
github.com
https://matrix.org/blog/2021/09/13/vulnerability-disclosure-key-sharing
matrix.org
https://github.com/matrix-org/matrix-js-sdk/security/advisories/GHSA-23cm-x6j7-6hq3
github.com
and 3 more references View all →

Timeline

Published
Sep 13, 2021
Last Updated
Nov 21, 2024

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