VDB-286747 · CVE-2024-52815 · Nessus 212753

element-hq synapse up to 1.120.0 Invite /sync denial of service

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
5.2	$0-$5k	0.00

Summaryinfo

A vulnerability classified as problematic has been found in element-hq synapse up to 1.120.0. Affected is an unknown function of the file /sync of the component Invite Handler. This manipulation causes denial of service. This vulnerability is tracked as CVE-2024-52815. The attack is possible to be carried out remotely. No exploit exists. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in element-hq synapse up to 1.120.0. It has been declared as problematic. Affected by this vulnerability is some unknown processing of the file /sync of the component Invite Handler. The manipulation with an unknown input leads to a denial of service vulnerability. The CWE definition for the vulnerability is CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. As an impact it is known to affect availability. The summary by CVE is:

Synapse is an open-source Matrix homeserver. Synapse versions before 1.120.1 fail to properly validate invites received over federation. This vulnerability allows a malicious server to send a specially crafted invite that disrupts the invited user's /sync functionality. Synapse 1.120.1 rejects such invalid invites received over federation and restores the ability to sync for affected users.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2024-52815 since 11/15/2024. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1499 according to MITRE ATT&CK.

The vulnerability scanner Nessus provides a plugin with the ID 212753 (Fedora 41 : matrix-synapse (2024-4cadba7a29)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 1.120.1 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (212753). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Vendor

element-hq

Name

synapse

Version

1.120

Website

Product: https://github.com/element-hq/synapse/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔍
CNA CVSS-BT Score: 🔍
CNA Vector: 🔍

CVSSv3info

VulDB Meta Base Score: 5.3
VulDB Meta Temp Score: 5.2

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 5.3
NVD Vector: 🔍

CVSSv2info

AV	AC	Au	C	I	A
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💳	💳	💳	💳	💳	💳
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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Denial of service
CWE: CWE-404
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Nessus ID: 212753
Nessus Name: Fedora 41 : matrix-synapse (2024-4cadba7a29)

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: synapse 1.120.1

Timelineinfo

11/15/2024 🔍
12/03/2024 +18 days 🔍
12/03/2024 +0 days 🔍
08/26/2025 +266 days 🔍

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CVE: CVE-2024-52815 (🔍)
GCVE (CVE): GCVE-0-2024-52815
GCVE (VulDB): GCVE-100-286747

Entryinfo

Created: 12/03/2024 18:24
Updated: 08/26/2025 17:44
Changes: 12/03/2024 18:24 (68), 12/13/2024 13:05 (2), 08/26/2025 17:44 (11)
Complete: 🔍
Cache ID: 216::103

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.