The pygrub boot loader emulator in Xen, when nul-delimited output format is requested, allows local pygrub-using guest OS administrators to read or delete arbitrary files on the host via NUL bytes in the bootloader configuration file.

The x86 emulator in Xen does not properly treat x86 NULL segments as unusable when accessing memory, which might allow local HVM guest users to gain privileges via vectors involving "unexpected" base/limit values.

Race condition in QEMU in Xen allows local x86 HVM guest OS administrators to gain privileges by changing certain data on shared rings, aka a "double fetch" vulnerability.

The pygrub boot loader emulator in Xen, when S-expression output format is requested, allows local pygrub-using guest OS administrators to read or delete arbitrary files on the host via string quotes and S-expressions in the bootloader configuration file.

Xen 4.0.x through 4.7.x mishandle x86 task switches to VM86 mode, which allows local 32-bit x86 HVM guest OS users to gain privileges or cause a denial of service (guest OS crash) by leveraging a guest operating system that uses hardware task switching and allows a new task to start in VM86 mode.

The x86 segment base write emulation functionality in Xen 4.4.x through 4.7.x allows local x86 PV guest OS administrators to cause a denial of service (host crash) by leveraging lack of canonical address checks.

Citrix Provisioning Services before 7.12 allows attackers to obtain sensitive kernel address information via unspecified vectors.

Use-after-free vulnerability in Citrix Provisioning Services before 7.12 allows attackers to execute arbitrary code via unspecified vectors.

Citrix Provisioning Services before 7.12 allows attackers to obtain sensitive information from kernel memory via unspecified vectors.

Buffer overflow in Citrix Provisioning Services before 7.12 allows attackers to execute arbitrary code via unspecified vectors.