CVE-2024-37303: synapse Missing Auth — Fix

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.

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CVSS v3.1 Score

5.3

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Weakness Type (CWE)

CWE-306 Missing Authentication

Affected Products

Vendor	Product	Versions
matrix	synapse	< 1.106.0

References

Advisories & Patches

https://github.com/element-hq/synapse/security/advisories/GHSA-gjgr-7834-rhxr https://github.com/matrix-org/matrix-spec-proposals/pull/3916

Frequently Asked Questions

What is CVE-2024-37303? +

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. It has a CVSS v3.1 base score of 5.3 (MEDIUM).

How severe is CVE-2024-37303? +

CVE-2024-37303 has a CVSS v3.1 score of 5.3 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

What products are affected by CVE-2024-37303? +

CVE-2024-37303 affects products from matrix, specifically: synapse. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2024-37303? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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