CVE-2021-21333

Publication date 26 March 2021

Last updated 24 July 2024


Ubuntu priority

Cvss 3 Severity Score

6.1 · Medium

Score breakdown

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.

Status

Package Ubuntu Release Status
matrix-synapse 24.10 oracular
Not affected
24.04 LTS noble
Not affected
23.10 mantic
Not affected
23.04 lunar
Not affected
22.10 kinetic
Not affected
22.04 LTS jammy
Not affected
21.10 impish
Not affected
21.04 hirsute
Not affected
20.10 groovy Ignored end of life
20.04 LTS focal
Needs evaluation
18.04 LTS bionic
Needs evaluation
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release

Severity score breakdown

Parameter Value
Base score 6.1 · Medium
Attack vector Network
Attack complexity High
Privileges required None
User interaction Required
Scope Changed
Confidentiality None
Integrity impact High
Availability impact None
Vector CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:N/I:H/A:N