CVE-2021-40823
matrix-js-sdk can be tricked into disclosing E2EE room keys to a participating homeserver
5.9
MEDIUM
CVSS 3.1
EPSS 0.16%
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.
How to fix CVE-2021-40823
To remediate CVE-2021-40823, upgrade the affected package to a fixed version below.
- —no fix listed
- —upgrade to 12.4.1 or later
Is CVE-2021-40823 being exploited?
Low — EPSS is 0.2%, meaning exploitation activity has not been observed at scale.
Affected packages (2)
- from 0
- from 0, < 12.4.1
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM5.9 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N |