CVE-2021-29471
published 2021-05-11CVE-2021-29471: Synapse is a Matrix reference homeserver written in python (pypi package matrix-synapse). Matrix is an ecosystem for open federated Instant Messaging and VoIP…
medium5.3CVSS 3.1
AVNACLPRNUINSUCNINAL
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 1.33.2 "Push rules" can specify conditions under which they will match, including `event_match`, which matches event content against a pattern including wildcards. Certain patterns can cause very poor performance in the matching engine, leading to a denial-of-service when processing moderate length events. The issue is patched in version 1.33.2. A potential workaround might be to prevent users from making custom push rules, by blocking such requests at a reverse-proxy.
Affected
4 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | matrix-synapse | < matrix-synapse 1.33.2-1 (forky) | matrix-synapse 1.33.2-1 (forky) |
| fedoraproject | fedora | — | — |
| matrix-org | synapse | < 1.33.2 | 1.33.2 |
| matrix | synapse | < 1.33.2 | 1.33.2 |
CVSS provenance
nvdv3.15.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
osv5.3MEDIUM