A flaw was found in the QEMU built-in VNC server. When a client connects to the VNC server, QEMU checks whether the current number of connections crosses a certain threshold and if so, cleans up the previous connection. If the previous connection happens to be in the handshake phase and fails, QEMU cleans up the connection again, resulting in a NULL pointer dereference issue. This could allow a remote unauthenticated client to cause a denial of service.
A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Qemu | Qemu | * | 8.1.0 (excluding) |
| Qemu | Qemu | 8.1.0-rc0 (including) | 8.1.0-rc0 (including) |
| Qemu | Qemu | 8.1.0-rc1 (including) | 8.1.0-rc1 (including) |