CVE-2021-21333
Published: 26 March 2021
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.
Priority
Status
| Package | Release | Status |
|---|---|---|
|
matrix-synapse Launchpad, Ubuntu, Debian |
bionic |
Needs triage
|
| focal |
Needs triage
|
|
| groovy |
Ignored
(end of life)
|
|
| hirsute |
Not vulnerable
(1.27.0-1)
|
|
| jammy |
Not vulnerable
(1.27.0-1)
|
|
| lunar |
Not vulnerable
(1.27.0-1)
|
|
| trusty |
Does not exist
|
|
| upstream |
Released
(1.27.0-1)
|
|
| xenial |
Does not exist
|
|
| impish |
Not vulnerable
(1.27.0-1)
|
|
| kinetic |
Not vulnerable
(1.27.0-1)
|
|
| mantic |
Not vulnerable
(1.27.0-1)
|
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 6.1 |
| 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 |
References
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-21333
- https://github.com/matrix-org/synapse/commit/e54746bdf7d5c831eabe4dcea76a7626f1de73df
- https://github.com/matrix-org/synapse/pull/9200
- https://github.com/matrix-org/synapse/releases/tag/v1.27.0
- https://github.com/matrix-org/synapse/security/advisories/GHSA-c5f8-35qr-q4fm
- NVD
- Launchpad
- Debian