Description
Matrix Javascript SDK is the Matrix Client-Server SDK for JavaScript. Prior to version 19.7.0, an attacker cooperating with a malicious homeserver can construct messages that legitimately appear to have come from another person, without any indication such as a grey shield. Additionally, a sophisticated attacker cooperating with a malicious homeserver could employ this vulnerability to perform a targeted attack in order to send fake to-device messages appearing to originate from another user. This can allow, for example, to inject the key backup secret during a self-verification, to make a targeted device start using a malicious key backup spoofed by the homeserver. These attacks are possible due to a protocol confusion vulnerability that accepts to-device messages encrypted with Megolm instead of Olm. Starting with version 19.7.0, matrix-js-sdk has been modified to only accept Olm-encrypted to-device messages. Out of caution, several other checks have been audited or added. This attack requires coordination between a malicious home server and an attacker, so those who trust their home servers do not need a workaround.
Published: 2022-09-28
Score: 8.6 High
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories
Source ID Title
EUVD EUVD EUVD-2022-6927 Matrix Javascript SDK is the Matrix Client-Server SDK for JavaScript. Prior to version 19.7.0, an attacker cooperating with a malicious homeserver can construct messages that legitimately appear to have come from another person, without any indication such as a grey shield. Additionally, a sophisticated attacker cooperating with a malicious homeserver could employ this vulnerability to perform a targeted attack in order to send fake to-device messages appearing to originate from another user. This can allow, for example, to inject the key backup secret during a self-verification, to make a targeted device start using a malicious key backup spoofed by the homeserver. These attacks are possible due to a protocol confusion vulnerability that accepts to-device messages encrypted with Megolm instead of Olm. Starting with version 19.7.0, matrix-js-sdk has been modified to only accept Olm-encrypted to-device messages. Out of caution, several other checks have been audited or added. This attack requires coordination between a malicious home server and an attacker, so those who trust their home servers do not need a workaround.
Github GHSA Github GHSA GHSA-r48r-j8fx-mq2c matrix-js-sdk subject to user spoofing via Olm/Megolm protocol confusion
Ubuntu USN Ubuntu USN USN-5724-1 Thunderbird vulnerabilities
History

Wed, 23 Apr 2025 17:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Subscriptions

Matrix Javascript Sdk
Redhat Enterprise Linux Rhel E4s Rhel Eus
cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2025-04-23T16:55:05.561Z

Reserved: 2022-09-02T00:00:00.000Z

Link: CVE-2022-39251

cve-icon Vulnrichment

Updated: 2024-08-03T12:00:43.351Z

cve-icon NVD

Status : Modified

Published: 2022-09-28T20:15:16.533

Modified: 2024-11-21T07:17:52.733

Link: CVE-2022-39251

cve-icon Redhat

Severity : Important

Publid Date: 2022-09-28T00:00:00Z

Links: CVE-2022-39251 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses