The IRQ setup in Xen 4.2.x and 4.3.x, when using device passthrough and configured to support a large number of CPUs, frees certain memory that may still be intended for use, which allows local guest administrators to cause a denial of service (memory corruption and hypervisor crash) and possibly execute arbitrary code via vectors related to an out-of-memory error that triggers a (1) use-after-free or (2) double free.

Xen 3.0.3 through 4.1.x (possibly 4.1.6.1), 4.2.x (possibly 4.2.3), and 4.3.x (possibly 4.3.1) does not properly prevent access to hypercalls, which allows local guest users to gain privileges via a crafted application running in ring 1 or 2.

The XEN_DOMCTL_getmemlist hypercall in Xen 3.4.x through 4.3.x (possibly 4.3.1) does not always obtain the page_alloc_lock and mm_rwlock in the same order, which allows local guest administrators to cause a denial of service (host deadlock).

Xen 4.2.x and 4.3.x, when using Intel VT-d and a PCI device has been assigned, does not clear the flag that suppresses IOMMU TLB flushes when unspecified errors occur, which causes the TLB entries to not be flushed and allows local guest administrators to cause a denial of service (host crash) or gain privileges via unspecified vectors.

Xen 4.2.x and 4.3.x, when using Intel VT-d for PCI passthrough, does not properly flush the TLB after clearing a present translation table entry, which allows local guest administrators to cause a denial of service or gain privileges via unspecified vectors related to an "inverted boolean parameter."

Xen 4.2.x and 4.3.x, when nested virtualization is disabled, does not properly check the emulation paths for (1) VMLAUNCH and (2) VMRESUME, which allows local HVM guest users to cause a denial of service (host crash) via unspecified vectors related to "guest VMX instruction execution."

The Ocaml xenstored implementation (oxenstored) in Xen 4.1.x, 4.2.x, and 4.3.x allows local guest domains to cause a denial of service (domain shutdown) via a large message reply.

Xen before 4.1.x, 4.2.x, and 4.3.x does not take the page_alloc_lock and grant_table.lock in the same order, which allows local guest administrators with access to multiple vcpus to cause a denial of service (host deadlock) via unspecified vectors.

Heap-based buffer overflow in QEMU 0.8.2, as used in Xen and possibly other products, allows local users to execute arbitrary code via crafted data in the "net socket listen" option, aka QEMU "net socket" heap overflow. NOTE: some sources have used CVE-2007-1321 to refer to this issue as part of "NE2000 network driver and the socket code," but this is the correct identifier for the individual net socket listen vulnerability.