PT-2024-23851 · Synapse+2 · Synapse+2

Alexeyshch · Published 2024-04-23 · Updated 2025-04-22 · CVE-2024-31208

Positive Technologies (AI Summary)

CVSS v3.1

6.5

Medium

Base vector

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

Name of the Vulnerable Software and Affected Versions Synapse versions prior to 1.105.1

Description A remote Matrix user with malicious intent, sharing a room with Synapse instances, 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.

Recommendations For versions prior to 1.105.1, server administrators should upgrade to 1.105.1 or later. As a temporary workaround, 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.

Exploit

Fix

DoS

Allocation of Resources Without Limits

Weakness Enumeration

CWE-770

Related Identifiers

CVE-2024-31208

GHSA-3H7Q-RFH9-XM4V

OPENSUSE-SU-2024:13897-1

PYSEC-2024-50

USN-7444-1

Affected Products

Linuxmint

Synapse

Ubuntu

References · 34

• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/31xxx/CVE-2024-31208.json · Exploit
• https://github.com/element-hq/synapse/commit/55b0aa847a61774b6a3acdc4b177a20dc019f01a · Patch
• https://github.com/element-hq/synapse/security/advisories/GHSA-3h7q-rfh9-xm4v · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2024-31208 · Security Note
• https://ubuntu.com/security/CVE-2023-42453 · Vendor Advisory
• https://lists.fedoraproject.org/archives/list/[e-mail]/message/VSF4NJJSTSQRJQ47PLYYSCFYKJBP7DET · Vendor Advisory
• https://osv.dev/vulnerability/GHSA-3h7q-rfh9-xm4v · Vendor Advisory
• https://lists.fedoraproject.org/archives/list/[e-mail]/message/R6FCCO4ODTZ3FDS7TMW76PKOSEL2TQVB · Vendor Advisory
• https://ubuntu.com/security/CVE-2024-31208 · Vendor Advisory
• https://ubuntu.com/security/CVE-2022-39374 · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2024-31208 · Vendor Advisory
• https://osv.dev/vulnerability/PYSEC-2024-50 · Vendor Advisory
• https://lists.fedoraproject.org/archives/list/[e-mail]/message/RR53FNHV446CB37TP45GZ6F6HZLZCK3K · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2024-31208 · Security Note
• https://ubuntu.com/security/CVE-2024-53863 · Vendor Advisory