Resource Exhaustion Affecting matrix-synapse package, versions <1.25.0-1
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Test your applications- Snyk ID SNYK-DEBIANUNSTABLE-MATRIXSYNAPSE-1080547
- published 27 Feb 2021
- disclosed 26 Feb 2021
Introduced: 26 Feb 2021
CVE-2021-21274 Open this link in a new tabHow to fix?
Upgrade Debian:unstable matrix-synapse to version 1.25.0-1 or higher.
NVD Description
Note: Versions mentioned in the description apply only to the upstream matrix-synapse package and not the matrix-synapse package as distributed by Debian.
See How to fix? for Debian:unstable relevant fixed versions and status.
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, a malicious homeserver could redirect requests to their .well-known file to a large file. This can lead to a denial of service attack where homeservers will consume significantly more resources when requesting the .well-known file of a malicious homeserver. This affects any server which accepts federation requests from untrusted servers. Issue is resolved in version 1.25.0. As a workaround the federation_domain_whitelist setting can be used to restrict the homeservers communicated with over federation.
References
- https://security-tracker.debian.org/tracker/CVE-2021-21274
- https://github.com/matrix-org/synapse/security/advisories/GHSA-2hwx-mjrm-v3g8
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/TNNAJOZNMVMXM6AS7RFFKB4QLUJ4IFEY/
- https://github.com/matrix-org/synapse/commit/ff5c4da1289cb5e097902b3e55b771be342c29d6
- https://github.com/matrix-org/synapse/pull/8950
- https://github.com/matrix-org/synapse/releases/tag/v1.25.0
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TNNAJOZNMVMXM6AS7RFFKB4QLUJ4IFEY/