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.
History

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cve-icon MITRE Information

Status: PUBLISHED

Assigner: GitHub_M

Published: 2021-04-12T21:50:14

Updated: 2021-08-02T02:06:34

Reserved: 2020-12-22T00:00:00


Link: CVE-2021-21392

JSON object: View

cve-icon NVD Information

Status : Modified

Published: 2021-04-12T22:15:13.147

Modified: 2023-11-07T03:30:00.343


Link: CVE-2021-21392

JSON object: View

cve-icon Redhat Information

No data.

CWE