CVE Vulnerability

CVE-2021-21392

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 1.28.0 requests to user provided domains were not restricted to external IP addresses when transitional IPv6 addresses were used. Outbound requests to federation, identity servers, when calculating the key validity for third-party invite events, sending push notifications, and generating URL previews are affected. This could cause Synapse to make requests to internal infrastructure on dual-stack networks. See referenced GitHub security advisory for details and workarounds.

4.9 /10

CVSS v2.0 :

V3 Legend

Vector :

Exploitability : 6.8 / Impact : 4.9

Attack Vector

Attack Complexity

Privileges Required

User Interaction

Confidentiality Impact PARTIAL

Integrity Impact PARTIAL

Availability Impact NONE

Scope

6.3 /10

CVSS v3.0 : MEDIUM

V3 Legend

Vector :

Exploitability : 2.1 / Impact : 4.2

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction REQUIRED

Confidentiality Impact LOW

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

References
Link Resource
https://pypi.org/project/matrix-synapse/ Product Third Party Advisory
https://github.com/matrix-org/synapse/security/advisories/GHSA-5wrh-4jwv-5w78 Patch Third Party Advisory
https://github.com/matrix-org/synapse/pull/9240 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

cpe:2.3:a:matrix:synapse:*:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*
Information

Published : 2021-04-12 10:15

Updated : 2021-11-23 10:36

NVD link : CVE-2021-21392

Mitre link : CVE-2021-21392

Products Affected
No products.
CWE
CWE-601

URL Redirection to Untrusted Site ('Open Redirect')