5.3

CVE-2021-29471

Denial of service in Matrix Synapse

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.
Daten sind bereitgestellt durch National Vulnerability Database (NVD)
Matrix ≫ Synapse Version < 1.33.2
Fedoraproject ≫ Fedora Version34
Zu dieser CVE wurde keine Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 1.65% 0.734
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
nvd@nist.gov 5.3 3.9 1.4
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
nvd@nist.gov 5 10 2.9
AV:N/AC:L/Au:N/C:N/I:N/A:P
security-advisories@github.com 3.7 2.2 1.4
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
CWE-331 Insufficient Entropy

The product uses an algorithm or scheme that produces insufficient entropy, leaving patterns or clusters of values that are more likely to occur than others.

CWE-400 Uncontrolled Resource Consumption

The product does not properly control the allocation and maintenance of a limited resource.

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TNNAJOZNMVMXM6AS7RFFKB4QLUJ4IFEY/
https://github.com/matrix-org/synapse/commit/03318a766cac9f8b053db2214d9c332a977d226c
Patch
Third Party Advisory
https://github.com/matrix-org/synapse/releases/tag/v1.33.2
Third Party Advisory
Release Notes
https://github.com/matrix-org/synapse/security/advisories/GHSA-x345-32rc-8h85
Patch
Third Party Advisory