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 1.25.0, 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.
Analysis and contextual insights are available on OpenCVE Cloud.
Remediation
No vendor fix or workaround currently provided.
Additional remediation guidance may be available on OpenCVE Cloud.
Tracking
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Advisories
| Source | ID | Title |
|---|---|---|
EUVD |
EUVD-2021-0124 | 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. |
Github GHSA |
GHSA-2hwx-mjrm-v3g8 | Denial of service attack via .well-known lookups |
References
History
No history.
Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2024-08-03T18:09:15.070Z
Reserved: 2020-12-22T00:00:00.000Z
Link: CVE-2021-21274
No data.
Status : Modified
Published: 2021-02-26T18:15:12.237
Modified: 2024-11-21T05:47:54.520
Link: CVE-2021-21274
No data.
OpenCVE Enrichment
No data.
EUVD
Github GHSA