CVE-2024-31208 Synapse's V2 state resolution weakness allows DoS from remote room members

What is CVE-2024-31208?

CVE-2024-31208 is a medium-severity vulnerability in Fedoraproject Fedora, published on 23 Apr 2024.

Official 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.

Weakness: CWE-770

Which versions are affected by CVE-2024-31208?

3 open source packages ship an affected version, including matrix-synapse. It affects 2 products.

Products include Fedoraproject Fedora, Matrix Synapse.

How do I fix CVE-2024-31208?

Upgrade matrix-synapse to 1.105.1 or later.

Is CVE-2024-31208 being exploited?

There is no known exploitation of CVE-2024-31208 in the wild and no public exploit code.

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• CVE-2021-39226 Grafana Authentication Bypass Exploited Critical 9.8
• CVE-2019-5544 VMware ESXi and Horizon DaaS OpenSLP Heap-Based Buffer Overflow Exploited Critical 9.8
• CVE-2024-4947 Google Chromium V8 Type Confusion Exploited Critical 9.6
• CVE-2024-4671 Google Chromium Visuals Use-After-Free Exploited Critical 9.6

All Fedoraproject Fedora vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-3h7q-rfh9-xm4v, PYSEC-2024-50, UBUNTU-CVE-2024-31208, openSUSE-SU-2024:13897-1.