CVE-2021-21333

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.

CVSS v3.0 6.1 MEDIUM
CVSS v2.0 2.6 LOW

6.1^/10

CVSS v3.0 : MEDIUM

Vector :

Exploitability : 1.6 / Impact : 4.0

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact NONE

Integrity Impact HIGH

Availability Impact NONE

Scope CHANGED

2.6^/10

CVSS v2.0 : LOW

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

Exploitability : 4.9 / Impact : 2.9

Access Vector NETWORK

Access Complexity HIGH

Authentication NONE

Confidentiality Impact NONE

Integrity Impact PARTIAL

Availability Impact NONE

References

Link	Resource
https://github.com/matrix-org/synapse/pull/9200	Patch Third Party Advisory
https://github.com/matrix-org/synapse/commit/e54746bdf7d5c831eabe4dcea76a7626f1de73df	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
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/TNNAJOZNMVMXM6AS7RFFKB4QLUJ4IFEY/	Mailing List Third Party Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:matrix:synapse:*:*:*:*:*:*:*:*

Configuration 2 (hide)

cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*

Information

Published : 2021-03-26 20:15

Updated : 2021-11-23 22:32

NVD link : CVE-2021-21333

Mitre link : CVE-2021-21333

JSON object : View

Products Affected

fedoraproject

fedora

matrix

synapse

CWE

CWE-74

Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')

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