matrix-js-sdk up to 19.6.x Message key exchange without entity authentication

Summaryinfo

A vulnerability, which was classified as critical, has been found in matrix-js-sdk up to 19.6.x. This impacts an unknown function of the component Message Handler. The manipulation leads to key exchange without entity authentication. This vulnerability is referenced as CVE-2022-39251. Remote exploitation of the attack is possible. No exploit is available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in matrix-js-sdk up to 19.6.x. It has been rated as critical. This issue affects an unknown functionality of the component Message Handler. The manipulation with an unknown input leads to a key exchange without entity authentication vulnerability. Using CWE to declare the problem leads to CWE-322. The product performs a key exchange with an actor without verifying the identity of that actor. Impacted is integrity. The summary by CVE is:

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.

The weakness was published 09/29/2022 as GHSA-r48r-j8fx-mq2c. It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2022-39251 since 09/02/2022. The technical details are unknown and an exploit is not publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 208577 (CentOS 7 : thunderbird (RHSA-2022:7184)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 19.7.0 eliminates this vulnerability. The upgrade is hosted for download at github.com. Applying the patch a587d7c36026fe1fcf93dfff63588abee359be76 is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at Tenable (208577). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Name

• matrix-js-sdk

Version

• 19.0
• 19.1
• 19.2
• 19.3
• 19.4
• 19.5
• 19.6

License

• open-source

CPE 2.3info

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CPE 2.2info

• 🔍
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Be aware that VulDB is the high quality source for vulnerability data.

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