CVE-2021-29471

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Summary

CVECVE-2021-29471
StatePUBLIC
Assigner[email protected]
Source PriorityCVE Program / NVD first with legacy fallback
Published2021-05-11 15:15:00 UTC
Updated2023-11-07 03:32:00 UTC
DescriptionSynapse 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.

Risk And Classification

Problem Types: CWE-331

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Operating System Fedoraproject Fedora 34 All All All
Application Matrix Synapse All All All All

References

ReferenceSourceLinkTags
Release v1.33.2 · matrix-org/synapse · GitHub MISC github.com
Denial of service attack via push rule patterns · Advisory · matrix-org/synapse · GitHub CONFIRM github.com
[SECURITY] Fedora 34 Update: matrix-synapse-1.38.1-1.fc34 - package-announce - Fedora Mailing-Lists lists.fedoraproject.org
[SECURITY] Fedora 34 Update: matrix-synapse-1.38.1-1.fc34 - package-announce - Fedora Mailing-Lists FEDORA lists.fedoraproject.org
Merge pull request from GHSA-x345-32rc-8h85 · matrix-org/synapse@03318a7 · GitHub MISC github.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Legacy QID Mappings

  • 281765 Fedora Security Update for matrix (FEDORA-2021-a627cfd31e)
  • 501695 Alpine Linux Security Update for synapse
  • 501926 Alpine Linux Security Update for synapse
  • 690141 Free Berkeley Software Distribution (FreeBSD) Security Update for py-matrix-synapse (278561d7-b261-11eb-b788-901b0e934d69)
  • 981379 Python (pip) Security Update for matrix-synapse (GHSA-x345-32rc-8h85)
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