Attacker Value
Unknown
(0 users assessed)
Exploitability
Unknown
(0 users assessed)
User Interaction
None
Privileges Required
None
Attack Vector
Network
0

CVE-2022-39249

Disclosure Date: September 28, 2022
Add MITRE ATT&CK tactics and techniques that apply to this CVE.

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 appearing to have come from another person. Such messages will be marked with a grey shield on some platforms, but this may be missing in others. This attack is possible due to the matrix-js-sdk implementing a too permissive key forwarding strategy on the receiving end. Starting with version 19.7.0, the default policy for accepting key forwards has been made more strict in the matrix-js-sdk. matrix-js-sdk will now only accept forwarded keys in response to previously issued requests and only from own, verified devices. The SDK now sets a trusted flag on the decrypted message upon decryption, based on whether the key used to decrypt the message was received from a trusted source. Clients need to ensure that messages decrypted with a key with trusted = false are decorated appropriately, for example, by showing a warning for such messages. This attack requires coordination between a malicious homeserver and an attacker, and those who trust your homeservers do not need a workaround.

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CVSS V3 Severity and Metrics
Base Score:
7.5 High
Impact Score:
3.6
Exploitability Score:
3.9
Vector:
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Attack Vector (AV):
Network
Attack Complexity (AC):
Low
Privileges Required (PR):
None
User Interaction (UI):
None
Scope (S):
Unchanged
Confidentiality (C):
None
Integrity (I):
High
Availability (A):
None

General Information

Vendors

  • matrix

Products

  • javascript sdk
Technical Analysis