This indicates an attack attempt to exploit a Denial of Service vulnerability in GNOME Project Vino.
The vulnerability is due to an error when vulnerable software handles a crafted authentication request. A remote attacker may be able to exploit this to cause a denial of service condition on the affected system.
GNOME Project Vino 3.9.x prior to 3.9.92
GNOME Project Vino 3.x prior to 3.8.2
Denial of Service: Remote attackers can crash vulnerable systems or services
Apply the most recent upgrade or patch from the vendor.