Xen, when running on a 64-bit hypervisor, allows local x86 guest OS users to modify arbitrary memory and consequently obtain sensitive information, cause a denial of service (host crash), or execute arbitrary code on the host by leveraging broken emulation of bit test instructions.
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.
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.
Incorrect access control mechanisms in Citrix Receiver Desktop Lock 4.5 allow an attacker to bypass the authentication requirement by leveraging physical access to a VDI for temporary disconnection of a LAN cable. NOTE: as of 20161208, the vendor could not reproduce the issue, stating "the researcher was unable to provide us with information that would allow us to confirm the behaviour and, despite extensive investigation on test deployments of supported products, we were unable to reproduce the behaviour as he described. The researcher has also, despite additional requests for information, ceased to respond to us."
Unauthorized redirect vulnerability in Citrix NetScaler ADC before 10.1 135.8, 10.5 61.11, 11.0 65.31/65.35F and 11.1 47.14 allows a remote attacker to steal session cookies of a legitimate AAA user via manipulation of Host header.