5.9
MEDIUM
CVE-2021-40824
Element Android/Matrix SDK for Android Key Stealing Vulnerability
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.

INFO

Published Date :

Sept. 13, 2021, 7:15 p.m.

Last Modified :

Nov. 21, 2024, 6:24 a.m.

Remotely Exploitable :

Yes !

Impact Score :

3.6

Exploitability Score :

2.2
Affected Products

The following products are affected by CVE-2021-40824 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Matrix element
2 Matrix matrix-android-sdk2
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2021-40824.

URL Resource
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

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2021-40824 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2021-40824 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by af854a3a-2127-422b-91ae-364da2661108

    Nov. 21, 2024

    Action Type Old Value New Value
    Added Reference https://github.com/matrix-org/matrix-android-sdk2/releases/tag/v1.2.2
    Added Reference https://matrix.org/blog/2021/09/13/vulnerability-disclosure-key-sharing
  • CVE Modified by [email protected]

    May. 14, 2024

    Action Type Old Value New Value
  • CWE Remap by [email protected]

    Aug. 08, 2023

    Action Type Old Value New Value
    Changed CWE CWE-327 CWE-290
  • Initial Analysis by [email protected]

    Sep. 24, 2021

    Action Type Old Value New Value
    Added CVSS V2 NIST (AV:N/AC:M/Au:N/C:P/I:N/A:N)
    Added CVSS V3.1 NIST AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
    Changed Reference Type https://github.com/matrix-org/matrix-android-sdk2/releases/tag/v1.2.2 No Types Assigned https://github.com/matrix-org/matrix-android-sdk2/releases/tag/v1.2.2 Patch, Third Party Advisory
    Changed Reference Type https://matrix.org/blog/2021/09/13/vulnerability-disclosure-key-sharing No Types Assigned https://matrix.org/blog/2021/09/13/vulnerability-disclosure-key-sharing Vendor Advisory
    Added CWE NIST CWE-327
    Added CPE Configuration OR *cpe:2.3:a:matrix:element:*:*:*:*:*:android:*:* versions up to (excluding) 1.2.2 *cpe:2.3:a:matrix:matrix-android-sdk2:*:*:*:*:*:android:*:* versions up to (excluding) 1.2.2
  • CVE Modified by [email protected]

    Sep. 14, 2021

    Action Type Old Value New Value
    Changed 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 leads to a situation where identity verification is inadequate and thus a key-requesting device can be impersonated. 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.
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
Exploit Prediction

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.

0.08 }} 0.00%

score

0.37855

percentile

CVSS31 - Vulnerability Scoring System
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability