Bug 2124168 (CVE-2022-31152)

Summary:	CVE-2022-31152 synapse: Denial of service due to incorrect application of event authorization rules
Product:	[Other] Security Response	Reporter:	Sandipan Roy <saroy>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED UPSTREAM	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	michel, mtasaka, renich, tonet666p
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
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Clone Of:		Environment:
Last Closed:	2022-09-05 22:45:47 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	2124169
Bug Blocks:

Description Sandipan Roy 2022-09-05 06:09:52 UTC

Synapse is an open-source Matrix homeserver written and maintained by the Matrix.org Foundation. The Matrix specification specifies a list of [event authorization rules](https://spec.matrix.org/v1.2/rooms/v9/#authorization-rules) which must be checked when determining if an event should be accepted into a room. In versions of Synapse up to and including version 1.61.0, some of these rules are not correctly applied. An attacker could craft events which would be accepted by Synapse but not a spec-conformant server, potentially causing divergence in the room state between servers. Administrators of homeservers with federation enabled are advised to upgrade to version 1.62.0 or higher. Federation can be disabled by setting [`federation_domain_whitelist`](https://matrix-org.github.io/synapse/latest/usage/configuration/config_documentation.html#federation_domain_whitelist) to an empty list (`[]`) as a workaround.

https://github.com/matrix-org/synapse/pull/13087
https://github.com/matrix-org/synapse/pull/13088
https://github.com/matrix-org/synapse/releases/tag/v1.62.0
https://github.com/matrix-org/synapse/security/advisories/GHSA-jhjh-776m-4765

Comment 1 Sandipan Roy 2022-09-05 06:10:07 UTC

Created synapse tracking bugs for this issue:

Affects: fedora-all [bug 2124169]

Comment 2 Product Security DevOps Team 2022-09-05 22:45:45 UTC

This CVE Bugzilla entry is for community support informational purposes only as it does not affect a package in a commercially supported Red Hat product. Refer to the dependent bugs for status of those individual community products.