CVE-2021-41281

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Summary

CVECVE-2021-41281
StatePUBLIC
Assigner[email protected]
Source PriorityCVE Program / NVD first with legacy fallback
Published2021-11-23 20:15:00 UTC
Updated2023-11-07 03:38:00 UTC
DescriptionSynapse is a package for Matrix homeservers written in Python 3/Twisted. Prior to version 1.47.1, Synapse instances with the media repository enabled can be tricked into downloading a file from a remote server into an arbitrary directory. No authentication is required for the affected endpoint. The last 2 directories and file name of the path are chosen randomly by Synapse and cannot be controlled by an attacker, which limits the impact. Homeservers with the media repository disabled are unaffected. Homeservers with a federation whitelist are also unaffected, since Synapse will check the remote hostname, including the trailing `../`s, against the whitelist. Server administrators should upgrade to 1.47.1 or later. Server administrators using a reverse proxy could, at the expense of losing media functionality, may block the certain endpoints as a workaround. Alternatively, non-containerized deployments can be adapted to use the hardened systemd config.

Risk And Classification

Problem Types: CWE-22

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Operating System Fedoraproject Fedora 34 All All All
Operating System Fedoraproject Fedora 35 All All All
Application Matrix Synapse All All All All

References

ReferenceSourceLinkTags
[SECURITY] Fedora 34 Update: matrix-synapse-1.48.0-1.fc34 - package-announce - Fedora Mailing-Lists FEDORA lists.fedoraproject.org
[SECURITY] Fedora 35 Update: matrix-synapse-1.48.0-1.fc35 - package-announce - Fedora Mailing-Lists FEDORA lists.fedoraproject.org
Prevent the media store from writing outside of the configured directory · matrix-org/synapse@91f2bd0 · GitHub MISC github.com
[SECURITY] Fedora 34 Update: matrix-synapse-1.48.0-1.fc34 - package-announce - Fedora Mailing-Lists lists.fedoraproject.org
Release v1.47.1 · matrix-org/synapse · GitHub MISC github.com
[SECURITY] Fedora 35 Update: matrix-synapse-1.48.0-1.fc35 - package-announce - Fedora Mailing-Lists lists.fedoraproject.org
Path traversal when downloading remote media · Advisory · matrix-org/synapse · GitHub CONFIRM github.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Legacy QID Mappings

  • 282099 Fedora Security Update for matrix (FEDORA-2021-2f9dcdbace)
  • 282130 Fedora Security Update for matrix (FEDORA-2021-9758549fce)
  • 502189 Alpine Linux Security Update for synapse
  • 690482 Free Berkeley Software Distribution (FreeBSD) Security Update for py-matrix-synapse (27aa2253-4c72-11ec-b6b9-e86a64caca56)
  • 980024 Python (pip) Security Update for matrix-synapse (GHSA-3hfw-x7gx-437c)
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