continuwuity is a Matrix homeserver written in Rust. Prior to version 0.5.0, this vulnerability allows a remote, unauthenticated attacker to force the target server to cryptographically sign arbitrary membership events. The flaw exists because the server fails to validate the origin of a signing request, provided the event's state_key is a valid user ID belonging to the target server. This issue has been patched in version 0.5.0. A workaround for this issue involves blocking access to the PUT /_matrix/federation/v2/invite/{roomId}/{eventId} endpoint using the reverse proxy.
| Métrique | Valeur | Interprétation |
|---|---|---|
|
AV (Vecteur d'Attaque)
Attack Vector
|
Network (N)
|
Exploit possible à distance via réseau (HTTP, API, etc.) |
|
AC (Complexité d'Attaque)
Attack Complexity
|
Low (L)
|
Peu de conditions requises pour exploiter |
|
PR (Privilèges Requis)
Privileges Required
|
None (N)
|
Aucune authentification requise |
|
UI (Interaction Utilisateur)
User Interaction
|
None (N)
|
Aucune interaction utilisateur nécessaire |
|
S (Périmètre)
Scope
|
Unchanged (U)
|
Impact reste dans le périmètre du composant compromis |
|
C (Impact Confidentialité)
Confidentiality Impact
|
High (H)
|
Divulgation totale d'informations |
|
I (Impact Intégrité)
Integrity Impact
|
High (H)
|
Modification totale des données possible |
|
A (Impact Disponibilité)
Availability Impact
|
High (H)
|
Interruption totale du service possible |
Conduit-derived homeservers are affected by a Confused Deputy and Improper Input Validation issue