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National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2021-29471 Detail

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 1.33.2 "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.


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

References to Advisories, Solutions, and Tools

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

Weakness Enumeration

CWE-ID CWE Name Source
CWE-331 Insufficient Entropy cwe source acceptance level NIST  
CWE-400 Uncontrolled Resource Consumption GitHub, Inc.  

Known Affected Software Configurations Switch to CPE 2.2

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Change History

5 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2021-29471
NVD Published Date:
05/11/2021
NVD Last Modified:
11/06/2023
Source:
GitHub, Inc.