Vulnerability 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.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Matrix | Javascript Sdk | < 12.4.1 |
Related Weaknesses (CWE)
References
- https://github.com/matrix-org/matrix-js-sdk/releases/tag/v12.4.1Third Party Advisory
- https://matrix.org/blog/2021/09/13/vulnerability-disclosure-key-sharingVendor Advisory
- https://github.com/matrix-org/matrix-js-sdk/releases/tag/v12.4.1Third Party Advisory
- https://matrix.org/blog/2021/09/13/vulnerability-disclosure-key-sharingVendor Advisory
FAQ
What is CVE-2021-40823?
CVE-2021-40823 is a vulnerability with a CVSS score of 5.9 (MEDIUM). 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 encryptio...
How severe is CVE-2021-40823?
CVE-2021-40823 has been rated MEDIUM with a CVSS base score of 5.9/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2021-40823?
Check the references section above for vendor advisories and patch information. Affected products include: Matrix Javascript Sdk.