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.
References (2)
Core 2
Core References
Vendor Advisory x_refsource_misc
https://matrix.org/blog/2021/09/13/vulnerability-disclosure-key-sharing
Patch, Third Party Advisory x_refsource_misc
https://github.com/matrix-org/matrix-android-sdk2/releases/tag/v1.2.2
Scores
CVSS v3
5.9
EPSS
0.0064
EPSS Percentile
45.8%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
Details
CWE
CWE-290
Status
published
Products (3)
matrix/element
< 1.2.2
matrix/matrix-android-sdk2
< 1.2.2
org.matrix.android/matrix-android-sdk2
0 - 1.2.2Maven
Published
Sep 13, 2021
Tracked Since
Feb 18, 2026