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CVE-2021-40823: Use of a Broken or Risky Cryptographic Algorithm

September 13, 2021 (updated August 8, 2023)

There is a logic error in the room key sharing functionality of matrix-js-sdk (aka Matrix Javascript SDK). This allows the homeserver to decrypt end-to-end encrypted messages sent by affected clients.

References

  • matrix.org/blog/2021/09/13/vulnerability-disclosure-key-sharing
  • nvd.nist.gov/vuln/detail/CVE-2021-40823

Code Behaviors & Features

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Affected versions

All versions before 12.4.1

Fixed versions

  • 12.4.1

Solution

Upgrade to version 12.4.1 or above.

Impact 5.9 MEDIUM

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Learn more about CVSS

Weakness

  • CWE-290: Authentication Bypass by Spoofing

Source file

npm/matrix-js-sdk/CVE-2021-40823.yml

Spotted a mistake? Edit the file on GitLab.

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