National Vulnerability Database

National Vulnerability Database

National Vulnerability
Database

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Search Parameters:
  • Contains Software Flaws (CVE)
  • CPE Product Version: cpe:/o:xen:xen:4.2.0
There are 203 matching records.
Displaying matches 1 through 20.
Vuln ID Summary CVSS Severity
CVE-2019-18425

An issue was discovered in Xen through 4.12.x allowing 32-bit PV guest OS users to gain guest OS privileges by installing and using descriptors. There is missing descriptor table limit checking in x86 PV emulation. When emulating certain PV guest operations, descriptor table accesses are performed by the emulating code. Such accesses should respect the guest specified limits, unless otherwise guaranteed to fail in such a case. Without this, emulation of 32-bit guest user mode calls through call gates would allow guest user mode to install and then use descriptors of their choice, as long as the guest kernel did not itself install an LDT. (Most OSes don't install any LDT by default). 32-bit PV guest user mode can elevate its privileges to that of the guest kernel. Xen versions from at least 3.2 onwards are affected. Only 32-bit PV guest user mode can leverage this vulnerability. HVM, PVH, as well as 64-bit PV guests cannot leverage this vulnerability. Arm systems are unaffected.

Published: October 31, 2019; 10:15:12 AM -04:00
V3.1: 9.8 CRITICAL
    V2: 9.3 HIGH
CVE-2019-18424

An issue was discovered in Xen through 4.12.x allowing attackers to gain host OS privileges via DMA in a situation where an untrusted domain has access to a physical device. This occurs because passed through PCI devices may corrupt host memory after deassignment. When a PCI device is assigned to an untrusted domain, it is possible for that domain to program the device to DMA to an arbitrary address. The IOMMU is used to protect the host from malicious DMA by making sure that the device addresses can only target memory assigned to the guest. However, when the guest domain is torn down, or the device is deassigned, the device is assigned back to dom0, thus allowing any in-flight DMA to potentially target critical host data. An untrusted domain with access to a physical device can DMA into host memory, leading to privilege escalation. Only systems where guests are given direct access to physical devices capable of DMA (PCI pass-through) are vulnerable. Systems which do not use PCI pass-through are not vulnerable.

Published: October 31, 2019; 10:15:12 AM -04:00
V3.1: 6.8 MEDIUM
    V2: 6.9 MEDIUM
CVE-2019-18422

An issue was discovered in Xen through 4.12.x allowing ARM guest OS users to cause a denial of service or gain privileges by leveraging the erroneous enabling of interrupts. Interrupts are unconditionally unmasked in exception handlers. When an exception occurs on an ARM system which is handled without changing processor level, some interrupts are unconditionally enabled during exception entry. So exceptions which occur when interrupts are masked will effectively unmask the interrupts. A malicious guest might contrive to arrange for critical Xen code to run with interrupts erroneously enabled. This could lead to data corruption, denial of service, or possibly even privilege escalation. However a precise attack technique has not been identified.

Published: October 31, 2019; 10:15:10 AM -04:00
V3.1: 8.8 HIGH
    V2: 8.5 HIGH
CVE-2019-18421

An issue was discovered in Xen through 4.12.x allowing x86 PV guest OS users to gain host OS privileges by leveraging race conditions in pagetable promotion and demotion operations. There are issues with restartable PV type change operations. To avoid using shadow pagetables for PV guests, Xen exposes the actual hardware pagetables to the guest. In order to prevent the guest from modifying these page tables directly, Xen keeps track of how pages are used using a type system; pages must be "promoted" before being used as a pagetable, and "demoted" before being used for any other type. Xen also allows for "recursive" promotions: i.e., an operating system promoting a page to an L4 pagetable may end up causing pages to be promoted to L3s, which may in turn cause pages to be promoted to L2s, and so on. These operations may take an arbitrarily large amount of time, and so must be re-startable. Unfortunately, making recursive pagetable promotion and demotion operations restartable is incredibly complicated, and the code contains several races which, if triggered, can cause Xen to drop or retain extra type counts, potentially allowing guests to get write access to in-use pagetables. A malicious PV guest administrator may be able to escalate their privilege to that of the host. All x86 systems with untrusted PV guests are vulnerable. HVM and PVH guests cannot exercise this vulnerability.

Published: October 31, 2019; 10:15:10 AM -04:00
V3.1: 7.5 HIGH
    V2: 7.1 HIGH
CVE-2019-18420

An issue was discovered in Xen through 4.12.x allowing x86 PV guest OS users to cause a denial of service via a VCPUOP_initialise hypercall. hypercall_create_continuation() is a variadic function which uses a printf-like format string to interpret its parameters. Error handling for a bad format character was done using BUG(), which crashes Xen. One path, via the VCPUOP_initialise hypercall, has a bad format character. The BUG() can be hit if VCPUOP_initialise executes for a sufficiently long period of time for a continuation to be created. Malicious guests may cause a hypervisor crash, resulting in a Denial of Service (DoS). Xen versions 4.6 and newer are vulnerable. Xen versions 4.5 and earlier are not vulnerable. Only x86 PV guests can exploit the vulnerability. HVM and PVH guests, and guests on ARM systems, cannot exploit the vulnerability.

Published: October 31, 2019; 10:15:10 AM -04:00
V3.1: 6.5 MEDIUM
    V2: 6.3 MEDIUM
CVE-2019-17349

An issue was discovered in Xen through 4.12.x allowing Arm domU attackers to cause a denial of service (infinite loop) involving a LoadExcl or StoreExcl operation.

Published: October 07, 2019; 09:15:11 PM -04:00
V3.1: 5.5 MEDIUM
    V2: 4.9 MEDIUM
CVE-2019-17348

An issue was discovered in Xen through 4.11.x allowing x86 PV guest OS users to cause a denial of service because of an incompatibility between Process Context Identifiers (PCID) and shadow-pagetable switching.

Published: October 07, 2019; 09:15:10 PM -04:00
V3.1: 6.5 MEDIUM
    V2: 4.9 MEDIUM
CVE-2019-17347

An issue was discovered in Xen through 4.11.x allowing x86 PV guest OS users to cause a denial of service or gain privileges because a guest can manipulate its virtualised %cr4 in a way that is incompatible with Linux (and possibly other guest kernels).

Published: October 07, 2019; 09:15:10 PM -04:00
V3.1: 7.8 HIGH
    V2: 4.6 MEDIUM
CVE-2019-17346

An issue was discovered in Xen through 4.11.x allowing x86 PV guest OS users to cause a denial of service or gain privileges because of an incompatibility between Process Context Identifiers (PCID) and TLB flushes.

Published: October 07, 2019; 09:15:10 PM -04:00
V3.1: 8.8 HIGH
    V2: 7.2 HIGH
CVE-2019-17344

An issue was discovered in Xen through 4.11.x allowing x86 PV guest OS users to cause a denial of service by leveraging a long-running operation that exists to support restartability of PTE updates.

Published: October 07, 2019; 09:15:10 PM -04:00
V3.1: 6.5 MEDIUM
    V2: 4.9 MEDIUM
CVE-2019-17343

An issue was discovered in Xen through 4.11.x allowing x86 PV guest OS users to cause a denial of service or gain privileges by leveraging incorrect use of the HVM physmap concept for PV domains.

Published: October 07, 2019; 09:15:10 PM -04:00
V3.1: 6.8 MEDIUM
    V2: 4.6 MEDIUM
CVE-2019-17342

An issue was discovered in Xen through 4.11.x allowing x86 PV guest OS users to cause a denial of service or gain privileges by leveraging a race condition that arose when XENMEM_exchange was introduced.

Published: October 07, 2019; 09:15:10 PM -04:00
V3.1: 7.0 HIGH
    V2: 4.4 MEDIUM
CVE-2019-17341

An issue was discovered in Xen through 4.11.x allowing x86 PV guest OS users to cause a denial of service or gain privileges by leveraging a page-writability race condition during addition of a passed-through PCI device.

Published: October 07, 2019; 09:15:10 PM -04:00
V3.1: 7.8 HIGH
    V2: 6.9 MEDIUM
CVE-2019-17340

An issue was discovered in Xen through 4.11.x allowing x86 guest OS users to cause a denial of service or gain privileges because grant-table transfer requests are mishandled.

Published: October 07, 2019; 09:15:10 PM -04:00
V3.1: 8.8 HIGH
    V2: 6.1 MEDIUM
CVE-2019-17351

An issue was discovered in drivers/xen/balloon.c in the Linux kernel before 5.2.3, as used in Xen through 4.12.x, allowing guest OS users to cause a denial of service because of unrestricted resource consumption during the mapping of guest memory, aka CID-6ef36ab967c7.

Published: October 07, 2019; 08:15:10 PM -04:00
V3.1: 6.5 MEDIUM
    V2: 4.9 MEDIUM
CVE-2019-17350

An issue was discovered in Xen through 4.12.x allowing Arm domU attackers to cause a denial of service (infinite loop) involving a compare-and-exchange operation.

Published: October 07, 2019; 08:15:10 PM -04:00
V3.1: 5.5 MEDIUM
    V2: 4.9 MEDIUM
CVE-2018-19967

An issue was discovered in Xen through 4.11.x on Intel x86 platforms allowing guest OS users to cause a denial of service (host OS hang) because Xen does not work around Intel's mishandling of certain HLE transactions associated with the KACQUIRE instruction prefix.

Published: December 07, 2018; 11:29:00 PM -05:00
V3.0: 6.5 MEDIUM
    V2: 4.9 MEDIUM
CVE-2018-19965

An issue was discovered in Xen through 4.11.x allowing 64-bit PV guest OS users to cause a denial of service (host OS crash) because #GP[0] can occur after a non-canonical address is passed to the TLB flushing code. NOTE: this issue exists because of an incorrect CVE-2017-5754 (aka Meltdown) mitigation.

Published: December 07, 2018; 11:29:00 PM -05:00
V3.0: 5.6 MEDIUM
    V2: 4.7 MEDIUM
CVE-2018-19962

An issue was discovered in Xen through 4.11.x on AMD x86 platforms, possibly allowing guest OS users to gain host OS privileges because small IOMMU mappings are unsafely combined into larger ones.

Published: December 07, 2018; 11:29:00 PM -05:00
V3.0: 7.8 HIGH
    V2: 6.9 MEDIUM
CVE-2018-19961

An issue was discovered in Xen through 4.11.x on AMD x86 platforms, possibly allowing guest OS users to gain host OS privileges because TLB flushes do not always occur after IOMMU mapping changes.

Published: December 07, 2018; 11:29:00 PM -05:00
V3.0: 7.8 HIGH
    V2: 6.9 MEDIUM