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This vulnerability has been modified since it was last analyzed by the NVD. It is awaiting reanalysis which may result in further changes to the information provided.
Description
An issue was discovered in Xen through 4.13.x, allowing x86 Intel HVM guest OS users to cause a host OS denial of service or possibly gain privileges because of insufficient cache write-back under VT-d. When page tables are shared between IOMMU and CPU, changes to them require flushing of both TLBs. Furthermore, IOMMUs may be non-coherent, and hence prior to flushing IOMMU TLBs, a CPU cache also needs writing back to memory after changes were made. Such writing back of cached data was missing in particular when splitting large page mappings into smaller granularity ones. A malicious guest may be able to retain read/write DMA access to frames returned to Xen's free pool, and later reused for another purpose. Host crashes (leading to a Denial of Service) and privilege escalation cannot be ruled out. Xen versions from at least 3.2 onwards are affected. Only x86 Intel systems are affected. x86 AMD as well as Arm systems are not affected. Only x86 HVM guests using hardware assisted paging (HAP), having a passed through PCI device assigned, and having page table sharing enabled can leverage the vulnerability. Note that page table sharing will be enabled (by default) only if Xen considers IOMMU and CPU large page size support compatible.
Metrics
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vector strings. CVSS information contributed by other sources is also
displayed.
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OR
*cpe:2.3:o:fedoraproject:fedora:31:*:*:*:*:*:*:*
*cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*
Added
CPE Configuration
OR
*cpe:2.3:o:opensuse:leap:15.1:*:*:*:*:*:*:*
*cpe:2.3:o:opensuse:leap:15.2:*:*:*:*:*:*:*
Changed
Reference Type
http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00024.html No Types Assigned
http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00024.html Mailing List, Third Party Advisory
Changed
Reference Type
http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00031.html No Types Assigned
http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00031.html Mailing List, Third Party Advisory
Changed
Reference Type
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/MXESCOVI7AVRNC7HEAMFM7PMEO6D3AUH/ No Types Assigned
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/MXESCOVI7AVRNC7HEAMFM7PMEO6D3AUH/ Mailing List, Third Party Advisory
Changed
Reference Type
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/VB3QJJZV23Z2IDYEMIHELWYSQBUEW6JP/ No Types Assigned
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/VB3QJJZV23Z2IDYEMIHELWYSQBUEW6JP/ Mailing List, Third Party Advisory
Changed
Reference Type
https://security.gentoo.org/glsa/202007-02 No Types Assigned
https://security.gentoo.org/glsa/202007-02 Third Party Advisory
CPE Deprecation Remap by NIST8/18/2020 11:05:58 AM
Action
Type
Old Value
New Value
Changed
CPE Configuration
OR
*cpe:2.3:o:debian:debian_linux:10:*:*:*:*:*:*:*
OR
*cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*