CVE-2024-37303

Synapse unauthenticated writes to the media repository allow planting of problematic content

Published Dec 3, 2024 CVSS 3.1 · 5.3 Medium EPSS < 1% KEV · Not listed
Description
Synapse is an open-source Matrix homeserver. Synapse before version 1.106 allows, by design, unauthenticated remote participants to trigger a download and caching of remote media from a remote homeserver to the local media repository. Such content then also becomes available for download from the local homeserver in an unauthenticated way. The implication is that unauthenticated remote adversaries can use this functionality to plant problematic content into the media repository. Synapse 1.106 introduces a partial mitigation in the form of new endpoints which require authentication for media downloads. The unauthenticated endpoints will be frozen in a future release, closing the attack vector.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
EUVD EUVD EUVD-2024-3472 Synapse is an open-source Matrix homeserver. Synapse before version 1.106 allows, by design, unauthenticated remote participants to trigger a download and caching of remote media from a remote homeserver to the local media repository. Such content then also becomes available for download from the local homeserver in an unauthenticated way. The implication is that unauthenticated remote adversaries can use this functionality to plant problematic content into the media repository. Synapse 1.106 introduces a partial mitigation in the form of new endpoints which require authentication for media downloads. The unauthenticated endpoints will be frozen in a future release, closing the attack vector.
Github GHSA Github GHSA GHSA-gjgr-7834-rhxr Synapse's unauthenticated writes to the media repository allow planting of problematic content
History
Type Values Removed Values Added
First Time appeared Matrix
Matrix synapse
CPEs cpe:2.3:a:matrix:synapse:*:*:*:*:*:*:*:*
Vendors & Products Matrix
Matrix synapse
Type Values Removed Values Added
First Time appeared Element-hq
Element-hq synapse
CPEs cpe:2.3:a:element-hq:synapse:*:*:*:*:*:*:*:*
Vendors & Products Element-hq
Element-hq synapse
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description Synapse is an open-source Matrix homeserver. Synapse before version 1.106 allows, by design, unauthenticated remote participants to trigger a download and caching of remote media from a remote homeserver to the local media repository. Such content then also becomes available for download from the local homeserver in an unauthenticated way. The implication is that unauthenticated remote adversaries can use this functionality to plant problematic content into the media repository. Synapse 1.106 introduces a partial mitigation in the form of new endpoints which require authentication for media downloads. The unauthenticated endpoints will be frozen in a future release, closing the attack vector.
Title Synapse unauthenticated writes to the media repository allow planting of problematic content
Weaknesses CWE-306
References
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Dec 3, 2024, 6:51 PM
Reserved
Jun 5, 2024, 8:10 PM
Status
Analyzed
Published
Dec 3, 2024, 5:15 PM
Modified
Jun 17, 2026, 7:38 AM