CVE-2021-21333

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.

Related CPE's


CvssV3 impact


BaseSeverity

MEDIUM

ConfidentialityImpact

NONE

AttackComplexity

HIGH

Scope

CHANGED

AttackVector

NETWORK

AvailabilityImpact

NONE

IntegrityImpact

HIGH

PrivilegesRequired

NONE

BaseScore

6.1

VectorString

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

Version

3.1

UserInteraction

REQUIRED

CvssV2 impact


AccessComplexity

HIGH

ConfidentialityImpact

NONE

AvailabilityImpact

NONE

IntegrityImpact

PARTIAL

BaseScore

2.6

VectorString

AV:N/AC:H/Au:N/C:N/I:P/A:N

Version

2.0

AccessVector

NETWORK

Authentication

NONE