CVE-2023-32682: matrix-org synapse Improper Authentication

Vulnerability summary

CVE-2023-32682 is a medium (CVSS 5.4) Improper Authentication vulnerability in matrix-org synapse. EPSS estimates a 0.75% chance of exploitation in the next 30 days, higher than 54.2% of scored vulnerabilities.

Timeline

1. 06-06-2023
   PublishedVulnerability first disclosed.
2. 13-02-2025
   Last modifiedVulnerability information updated.

Description

Synapse is a Matrix protocol homeserver written in Python with the Twisted framework. In affected versions it may be possible for a deactivated user to login when using uncommon configurations. This only applies if any of the following are true: 1. JSON Web Tokens are enabled for login via the `jwt_config.enabled` configuration setting. 2. The local password database is enabled via the `password_config.enabled` and `password_config.localdb_enabled` configuration settings *and* a user's password is updated via an admin API after a user is deactivated. Note that the local password database is enabled by default, but it is uncommon to set a user's password after they've been deactivated. Installations that are configured to only allow login via Single Sign-On (SSO) via CAS, SAML or OpenID Connect (OIDC); or via an external password provider (e.g. LDAP) are not affected. If not using JSON Web Tokens, ensure that deactivated users do not have a password set. This issue has been addressed in version 1.85.0. Users are advised to upgrade.

• CWE-287Improper AuthenticationWhen an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.