CVE-2021-21273

published 2021-02-26

CVE-2021-21273: Synapse is a Matrix reference homeserver written in python (pypi package matrix-synapse). Matrix is an ecosystem for open federated Instant Messaging and VoIP…

Priority P4 31 medium 6.1 CVSS 3.1

AV N AC L PR N UI R S C C L I L A N

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 1.25.0, requests to user provided domains were not restricted to external IP addresses when calculating the key validity for third-party invite events and sending push notifications. This could cause Synapse to make requests to internal infrastructure. The type of request was not controlled by the user, although limited modification of request bodies was possible. For the most thorough protection server administrators should remove the deprecated `federation_ip_range_blacklist` from their settings after upgrading to Synapse v1.25.0 which will result in Synapse using the improved default IP address restrictions. See the new `ip_range_blacklist` and `ip_range_whitelist` settings if more specific control is necessary.

Affected

4 ranges

Vendor	Product	Version range	Fixed in
debian	matrix-synapse	< matrix-synapse 1.25.0-1 (forky)	matrix-synapse 1.25.0-1 (forky)
fedoraproject	fedora	—	—
matrix-org	synapse	< 1.25.0	1.25.0
matrix	synapse	< 1.25.0	1.25.0

CVSS provenance

nvd v3.1 6.1 MEDIUM CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

nvd v2.0 5.8 MEDIUM AV:N/AC:M/Au:N/C:P/I:P/A:N

osv 6.1 MEDIUM

vendor_debian 3.1 LOW

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CWE-601