Upstream information

CVE-2021-21392 at MITRE

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 1.28.0 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.

SUSE information

Overall state of this security issue: Does not affect SUSE products

This issue is currently rated as having moderate severity.

CVSS v2 Scores
  National Vulnerability Database
Base Score 4.9
Vector AV:N/AC:M/Au:S/C:P/I:P/A:N
Access Vector Network
Access Complexity Medium
Authentication Single
Confidentiality Impact Partial
Integrity Impact Partial
Availability Impact None
CVSS v3 Scores
  National Vulnerability Database
Base Score 6.3
Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:H/A:N
Access Vector Network
Access Complexity Low
Privileges Required Low
User Interaction Required
Scope Unchanged
Confidentiality Impact Low
Integrity Impact High
Availability Impact None
CVSSv3 Version 3.1
SUSE Bugzilla entry: 1184754 [NEW]

No SUSE Security Announcements cross referenced.