The PCI backend driver in Xen, when running on an x86 system and using Linux 3.1.x through 4.3.x as the driver domain, allows local guest administrators to generate a continuous stream of WARN messages and cause a denial of service (disk consumption) by leveraging a system with access to a passed-through MSI or MSI-X capable physical PCI device and XEN_PCI_OP_enable_msi operations, aka "Linux pciback missing sanity checks."
This is a vulnerability exploitable with only local access requires the attacker to have either
physical access to the vulnerable system or a local (shell) account. Examples of locally
exploitable vulnerabilities are peripheral attacks such as Firewire/USB DMA attacks, and
local privilege escalations (e.g., sudo).
Specialized access conditions or extenuating circumstances do not exist. The following are examples:
The affected product typically requires access to a wide range of systems and users, possibly anonymous an untrusted (e.g., Internet-facing web or mail server).
The affected configuration is default or ubiquitous. The attack can be performed manually and requires little skill or additional information gathering.
The 'race condition' is a lazy one (i.e., it is technically a race but easily winnable).
One instance of authentication is required to access and exploit the vulnerability.
There is no impact to the confidentiality of the system.
There is no impact to the integrity of the system.
There is reduced performance or interruptions in resource availability. An example is
a network-based flood attack that permits a limited number of successful connections
to an Internet service.
NIST (National Institute of Standards and Technology) NVD (National Vulnerability Database)