Xen through 4.8.x does not validate the port numbers of polled event channel ports, which allows guest OS users to cause a denial of service (NULL pointer dereference and host OS crash) or possibly obtain sensitive information, aka XSA-221.
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 |
|---|---|---|---|
| Xen | Xen | * | 4.8.1 (including) |
| Xen | Ubuntu | devel | * |
| Xen | Ubuntu | trusty | * |
| Xen | Ubuntu | xenial | * |
| Xen | Ubuntu | yakkety | * |
| Xen | Ubuntu | zesty | * |