// For flags

CVE-2022-31152

Synapse vulnerable to denial of service (DoS) due to incorrect application of event authorization rules

Severity Score

7.5
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

Synapse is an open-source Matrix homeserver written and maintained by the Matrix.org Foundation. The Matrix specification specifies a list of [event authorization rules](https://spec.matrix.org/v1.2/rooms/v9/#authorization-rules) which must be checked when determining if an event should be accepted into a room. In versions of Synapse up to and including version 1.61.0, some of these rules are not correctly applied. An attacker could craft events which would be accepted by Synapse but not a spec-conformant server, potentially causing divergence in the room state between servers. Administrators of homeservers with federation enabled are advised to upgrade to version 1.62.0 or higher. Federation can be disabled by setting [`federation_domain_whitelist`](https://matrix-org.github.io/synapse/latest/usage/configuration/config_documentation.html#federation_domain_whitelist) to an empty list (`[]`) as a workaround.

Synapse es un servidor doméstico de Matrix de código abierto escrito y mantenido por la Fundación Matrix.org. La especificación de Matrix especifica una lista de [reglas de autorización de eventos](https://spec.matrix.org/v1.2/rooms/v9/#authorization-rules) que deben ser comprobadas cuando es determinado si un evento debe ser aceptado en una sala. En las versiones de Synapse hasta 1.61.0 incluyéndola, algunas de estas reglas no son aplicadas correctamente. Un atacante podría diseñar eventos que serían aceptados por Synapse pero no por un servidor conforme a las especificaciones, causando potencialmente una divergencia en el estado de la sala entre los servidores. Es recomendado a administradores de servidores domésticos con la federación activada que actualicen a versión 1.62.0 o superior. La federación puede ser deshabilitada al establecer ["federation_domain_whitelist"](https://matrix-org.github.io/synapse/latest/usage/configuration/config_documentation.html#federation_domain_whitelist) a una lista vacía ("[]") como una mitigación

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
Attack Vector
Network
Attack Complexity
High
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
High
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2022-05-18 CVE Reserved
  • 2022-09-02 CVE Published
  • 2024-04-23 EPSS Updated
  • 2024-08-03 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-703: Improper Check or Handling of Exceptional Conditions
  • CWE-755: Improper Handling of Exceptional Conditions
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Matrix
Search vendor "Matrix"
Synapse
Search vendor "Matrix" for product "Synapse"
< 1.62.0
Search vendor "Matrix" for product "Synapse" and version " < 1.62.0"
-
Affected