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
Link | Resource |
---|---|
https://github.com/matrix-org/synapse/releases/tag/v1.25.0 | Third Party Advisory |
https://github.com/matrix-org/synapse/commit/ff5c4da1289cb5e097902b3e55b771be342c29d6 | Patch Third Party Advisory |
https://github.com/matrix-org/synapse/pull/8950 | Patch Third Party Advisory |
https://github.com/matrix-org/synapse/security/advisories/GHSA-2hwx-mjrm-v3g8 | Patch Third Party Advisory |
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/TNNAJOZNMVMXM6AS7RFFKB4QLUJ4IFEY/ | Mailing List Third Party Advisory |
Information
Published : 2021-02-26 10:15
Updated : 2022-10-24 13:49
NVD link : CVE-2021-21274
Mitre link : CVE-2021-21274
JSON object : View
CWE
CWE-770
Allocation of Resources Without Limits or Throttling
Products Affected
matrix
- synapse
fedoraproject
- fedora