Xenserver

A statement in the System Programming Guide of the Intel 64 and IA-32 Architectures Software Developer's Manual (SDM) was mishandled in the development of some or all operating-system kernels, resulting in unexpected behavior for #DB exceptions that are deferred by MOV SS or POP SS, as demonstrated by (for example) privilege escalation in Windows, macOS, some Xen configurations, or FreeBSD, or a Linux kernel crash. The MOV to SS and POP SS instructions inhibit interrupts (including NMIs), data breakpoints, and single step trap exceptions until the instruction boundary following the next instruction (SDM Vol. 3A; section 6.8.3). (The inhibited data breakpoints are those on memory accessed by the MOV to SS or POP to SS instruction itself.) Note that debug exceptions are not inhibited by the interrupt enable (EFLAGS.IF) system flag (SDM Vol. 3A; section 2.3). If the instruction following the MOV to SS or POP to SS instruction is an instruction like SYSCALL, SYSENTER, INT 3, etc. that transfers control to the operating system at CPL < 3, the debug exception is delivered after the transfer to CPL < 3 is complete. OS kernels may not expect this order of events and may therefore experience unexpected behavior when it occurs.

Published: 2018-05-08T18:00:00.000Z
Updated: 2024-08-05T07:10:46.698Z

An issue was discovered in Linux Foundation xapi in Citrix XenServer through 7.0. An authenticated read-only administrator can cancel tasks of other administrators.

Published: 2017-01-30T16:00:00.000Z
Updated: 2024-08-05T15:04:15.332Z

An issue was discovered in Linux Foundation xapi in Citrix XenServer through 7.0. An authenticated read-only administrator can corrupt the host database.

Published: 2017-01-30T16:00:00.000Z
Updated: 2024-08-05T15:04:15.351Z

arch/x86/mm.c in Xen allows local PV guest OS users to gain host OS privileges via vectors related to map_grant_ref.

Published: 2017-08-24T14:00:00.000Z
Updated: 2024-08-05T18:28:16.519Z

Race condition in the grant table code in Xen 4.6.x through 4.9.x allows local guest OS administrators to cause a denial of service (free list corruption and host crash) or gain privileges on the host via vectors involving maptrack free list handling.

Published: 2017-08-24T14:00:00.000Z
Updated: 2024-08-05T18:28:16.501Z