CVE-2023-32682

Synapse has improper checks for deactivated users during login

Workarounds

If not using JSON Web Tokens, ensure that deactivated users do not have a password set. This list of users can be queried from PostgreSQL:

SELECT name FROM users WHERE password_hash IS NOT NULL AND deactivated = 1;

It may be possible for a deactivated user to login when using uncommon configurations.

This only applies if any of the following are true:

• JSON Web Tokens are enabled for login via the jwt_config.enabled configuration setting
• 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.

The application does not adequately verify the identity of a user, device, or process before granting access. Typical impact: unauthorized access to functions or data reserved for authenticated parties.

CVE-2023-32682 has a CVSS score of 5.4 (Medium). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (1.85.0); upgrading removes the vulnerable code path.

Kodem intelligence

Already deployed Kodem?

• If using JSON Web Token logins: #15624
• For other users: #15634

1. What is CVE-2023-32682? CVE-2023-32682 is a medium-severity improper authentication vulnerability in matrix-synapse (pip), affecting versions < 1.85.0. It is fixed in 1.85.0. The application does not adequately verify the identity of a user, device, or process before granting access.
2. How severe is CVE-2023-32682? CVE-2023-32682 has a CVSS score of 5.4 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of matrix-synapse are affected by CVE-2023-32682? matrix-synapse (pip) versions < 1.85.0 is affected.
4. Is there a fix for CVE-2023-32682? Yes. CVE-2023-32682 is fixed in 1.85.0. Upgrade to this version or later.
5. Is CVE-2023-32682 exploitable, and should I be worried? Whether CVE-2023-32682 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2023-32682 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2023-32682? Upgrade matrix-synapse to 1.85.0 or later.

Other vulnerabilities in matrix-synapse