Cross-site scripting (XSS) vulnerability in the XenAPI HTTP interfaces in Citrix XenServer Express, Standard, and Enterprise Edition 4.1.0; Citrix XenServer Dell Edition (Express and Enterprise) 4.1.0; and HP integrated Citrix XenServer (Select and Enterprise) 4.1.0 allows remote attackers to inject arbitrary web script or HTML via unspecified vectors.

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.

ntp: disabling synchronization via crafted KoD packet

The ntpd client in NTP 4.x before 4.2.8p4 and 4.3.x before 4.3.77 allows remote attackers to cause a denial of service via a number of crafted "KOD" messages.

xen: linux: Fix Xen block IO merge-ability calculation (XSA-229)

The xen_biovec_phys_mergeable function in drivers/xen/biomerge.c in Xen might allow local OS guest users to corrupt block device data streams and consequently obtain sensitive memory information, cause a denial of service, or gain host OS privileges by leveraging incorrect block IO merge-ability calculation.

xen: grant_table: Race conditions with maptrack free list handling (XSA-228)

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.

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

xen: x86 64-bit bit test instruction emulation broken (XSA-195)

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.

xen: x86 task switch to VM86 mode mis-handled (XSA-192)

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.

xen: x86 segment base write emulation lacking canonical address checks (XSA-193)

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.

Xen: qemu ioport out-of-bounds array access (XSA-199)

The (1) ioport_read and (2) ioport_write functions in Xen, when qemu is used as a device model within Xen, might allow local x86 HVM guest OS administrators to gain qemu process privileges via vectors involving an out-of-range ioport access.

xen: delimiter injection vulnerabilities in pygrub (XSA-198)

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: qemu incautious about shared ring processing (XSA-197)

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.

xen: delimiter injection vulnerabilities in pygrub (XSA-198)

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.

xen: x86: PV privilege escalation via map_grant_ref (XSA-227)

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

xen: possibly unbounded recursion in grant table code (XSA-226)

Xen allows local OS guest users to cause a denial of service (crash) or possibly obtain sensitive information or gain privileges via vectors involving transitive grants.

ntp: denial of service by trigerring rate limiting on NTP server

The rate limiting feature in NTP 4.x before 4.2.8p4 and 4.3.x before 4.3.77 allows remote attackers to have unspecified impact via a large number of crafted requests.

xen: x86 null segments not always treated as unusable (XSA-191)

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.

xen: x86 PV guests may be able to mask interrupts (XSA-202)

Xen through 4.8.x allows local x86 PV guest OS kernel administrators to cause a denial of service (host hang or crash) by modifying the instruction stream asynchronously while performing certain kernel operations.

xen: x86: missing NULL pointer check in VMFUNC emulation (XSA-203)

VMFUNC emulation in Xen 4.6.x through 4.8.x on x86 systems using AMD virtualization extensions (aka SVM) allows local HVM guest OS users to cause a denial of service (hypervisor crash) by leveraging a missing NULL pointer check.

xen: unmediated PCI register access in qemu (xsa-131)

QEMU does not properly restrict write access to the PCI config space for certain PCI pass-through devices, which might allow local x86 HVM guests to gain privileges, cause a denial of service (host crash), obtain sensitive information, or possibly have other unspecified impact via unknown vectors.