CVE-2024-31208: fedora DoS — Fix

Description

Synapse is an open-source Matrix homeserver. A remote Matrix user with malicious intent, sharing a room with Synapse instances before 1.105.1, can dispatch specially crafted events to exploit a weakness in the V2 state resolution algorithm. This can induce high CPU consumption and accumulate excessive data in the database of such instances, resulting in a denial of service. Servers in private federations, or those that do not federate, are not affected. Server administrators should upgrade to 1.105.1 or later. Some workarounds are available. One can ban the malicious users or ACL block servers from the rooms and/or leave the room and purge the room using the admin API.

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CVSS v3.1 Score

6.5

MEDIUM

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

Weakness Type (CWE)

CWE-770 CWE-770

Affected Products

Vendor	Product	Versions
matrix	synapse	< 1.105.1
fedoraproject	fedora	All
fedoraproject	fedora	All
fedoraproject	fedora	All

References

Advisories & Patches

https://github.com/element-hq/synapse/commit/55b0aa847a61774b6a3acdc4b177a20dc019f01a https://github.com/element-hq/synapse/security/advisories/GHSA-3h7q-rfh9-xm4v https://github.com/element-hq/synapse/commit/55b0aa847a61774b6a3acdc4b177a20dc019f01a https://github.com/element-hq/synapse/security/advisories/GHSA-3h7q-rfh9-xm4v

Other References

https://github.com/element-hq/synapse/releases/tag/v1.105.1 https://lists.fedoraproject.org/archives/list/[email protected]/message/R6FCCO4ODTZ3FDS7TMW76PKOSEL2TQVB/ https://lists.fedoraproject.org/archives/list/[email protected]/message/RR53FNHV446CB37TP45GZ6F6HZLZCK3K/ https://lists.fedoraproject.org/archives/list/[email protected]/message/VSF4NJJSTSQRJQ47PLYYSCFYKJBP7DET/ https://github.com/element-hq/synapse/releases/tag/v1.105.1 https://lists.fedoraproject.org/archives/list/[email protected]/message/R6FCCO4ODTZ3FDS7TMW76PKOSEL2TQVB/ https://lists.fedoraproject.org/archives/list/[email protected]/message/RR53FNHV446CB37TP45GZ6F6HZLZCK3K/ https://lists.fedoraproject.org/archives/list/[email protected]/message/VSF4NJJSTSQRJQ47PLYYSCFYKJBP7DET/

Frequently Asked Questions

What is CVE-2024-31208? +

Synapse is an open-source Matrix homeserver. A remote Matrix user with malicious intent, sharing a room with Synapse instances before 1.105.1, can dispatch specially crafted events to exploit a weakness in the V2 state resolution algorithm. This can induce high CPU consumption and accumulate excessive data in the database of such instances, resulting in a denial of service. Servers in private federations, or those that do not federate, are not affected. Server administrators should upgrade to 1.105.1 or later. Some workarounds are available. One can ban the malicious users or ACL block servers from the rooms and/or leave the room and purge the room using the admin API. It has a CVSS v3.1 base score of 6.5 (MEDIUM).

How severe is CVE-2024-31208? +

CVE-2024-31208 has a CVSS v3.1 score of 6.5 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-2024-31208? +

CVE-2024-31208 affects products from fedoraproject, matrix, specifically: fedora, synapse. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2024-31208? +

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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