CVE-2026-120749 Dbus: dbus-daemon: dbus-daemon aborts (reply_serial != 0) when a broadcast from the driver cannot be delivered to a monitored bus

Description

A flaw was found in D-Bus. With a privileged Monitoring client attached (for example dbus-monitor or busctl monitor), an unprivileged local user can cause dbus-daemon to abort if a driver-originated broadcast such as NameOwnerChanged or ActivatableServicesChanged cannot be delivered to a recipient (for example due to a deny rule or an exceeded outgoing message queue). Driver broadcasts still use serial 0; when delivery fails, composing the monitor error reply asserts reply_serial != 0 and aborts the daemon. This is an incomplete fix for CVE-2023-34969, which only assigned serials for driver messages sent to a single recipient. On the well-known system bus this is a denial of service.

Exploitable avec un accès local à la machine, sans compte et sans action d’un utilisateur ; un attaquant peut compromettre gravement la confidentialité, l’intégrité ou la disponibilité.

Vecteur d’attaque

Local

Complexité

Faible

Privilèges requis

Aucun

Interaction

Aucune

Portée

Inchangée

Confidentialité

Aucun

Intégrité

Aucun

Disponibilité

Élevé

Produits et versions touchés