CVE-2021-21333 Detail

Current Description

Synapse is a Matrix reference homeserver written in python (pypi package matrix-synapse). Matrix is an ecosystem for open federated Instant Messaging and VoIP. In Synapse before version 1.27.0, the notification emails sent for notifications for missed messages or for an expiring account are subject to HTML injection. In the case of the notification for missed messages, this could allow an attacker to insert forged content into the email. The account expiry feature is not enabled by default and the HTML injection is not controllable by an attacker. This is fixed in version 1.27.0.


View Analysis Description

Severity



CVSS 3.x Severity and Metrics:

NIST CVSS score matches with CNA score
CNA:  GitHub, Inc.
Base Score:  6.1 MEDIUM
Vector:  CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:N/I:H/A:N


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Note: The NVD and the CNA have provided the same score. When this occurs only the CNA information is displayed, but the Acceptance Level icon for the CNA is given a checkmark to signify NVD concurrence.

References to Advisories, Solutions, and Tools

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Hyperlink Resource
https://github.com/matrix-org/synapse/commit/e54746bdf7d5c831eabe4dcea76a7626f1de73df Patch  Third Party Advisory 
https://github.com/matrix-org/synapse/pull/9200 Patch  Third Party Advisory 
https://github.com/matrix-org/synapse/releases/tag/v1.27.0 Third Party Advisory 
https://github.com/matrix-org/synapse/security/advisories/GHSA-c5f8-35qr-q4fm Patch  Third Party Advisory 

Weakness Enumeration

CWE-ID CWE Name Source
CWE-74 Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection') Provider acceptance level GitHub, Inc.  

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Change History

1 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2021-21333
NVD Published Date:
03/26/2021
NVD Last Modified:
03/31/2021
Source:
GitHub, Inc.