CVEvulnerability
CVE-2021-40824
5.9 MEDIUM
Official page ↗
- Status
- Modified
- Published
- 2021-09-13
- Last modified
- 2026-06-17
- Assigner
- [email protected]
- CVSS 3.1 ([email protected])
- 5.9 MEDIUM — CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
- CVSS 2.0 ([email protected])
- 4.3 MEDIUM — AV:N/AC:M/Au:N/C:P/I:N/A:N
- Weaknesses
- CWE-290
Description
A logic error in the room key sharing functionality of Element Android before 1.2.2 and matrix-android-sdk2 (aka Matrix SDK for Android) before 1.2.2 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 attacker to decrypt end-to-end encrypted messages sent by affected clients.
Affected configurations
• matrix element (< 1.2.2)
• matrix matrix-android-sdk2 (< 1.2.2)
Related
Weakness · CWE (1)
- CWE-290 Authentication Bypass by Spoofing weakness
References
- https://github.com/matrix-org/matrix-android-sdk2/releases/tag/v1.2.2 Patch, Third Party Advisory
- https://matrix.org/blog/2021/09/13/vulnerability-disclosure-key-sharing Vendor Advisory
- https://github.com/matrix-org/matrix-android-sdk2/releases/tag/v1.2.2 Patch, Third Party Advisory
- https://matrix.org/blog/2021/09/13/vulnerability-disclosure-key-sharing Vendor Advisory