Vulnerability identifier: #VU67743

Vulnerability risk: Low

CVSSv3.1: 3.8 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2022-39251

CWE-ID: CWE-345

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Matrix Javascript SDK
Web applications / JS libraries

Vendor: Matrix.org

Description
he vulnerability allows a remote attacker to bypass implemented security restrictions.

The vulnerability exists due to a protocol confusion vulnerability that accepts to-device messages encrypted with Megolm instead of Olm. A remote attacker cooperating with a malicious home server can construct messages appearing to have come from another person without any indication such as a grey shield.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Matrix Javascript SDK: 0.1.0 - 19.6.0

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External links
http://github.com/matrix-org/matrix-js-sdk/commit/a587d7c36026fe1fcf93dfff63588abee359be76
http://github.com/matrix-org/matrix-js-sdk/releases/tag/v19.7.0
http://matrix.org/blog/2022/09/28/upgrade-now-to-address-encryption-vulns-in-matrix-sdks-and-clients
http://github.com/matrix-org/matrix-js-sdk/security/advisories/GHSA-r48r-j8fx-mq2c

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.