CVE-2020-25596

A flaw was found in Xen. One of Xen's sanitization paths injects a GP fault and incorrectly delivers it twice to the guest. This flaw allows malicious or buggy user space to crash the guest kernel, resulting in a VM denial of service. Mitigation Running only x86 PVH/HVM guests avoids the...

races with evtchn_reset()

ISSUE DESCRIPTION Uses of EVTCHNOPreset potentially by a guest on itself or XENDOMCTLsoftreset by itself covered by XSA-77 can lead to the violation of various internal assumptions. This may lead to out of bounds memory accesses or triggering of bug checks. IMPACT In particular x86 PV guests may ...

x86 pv: Crash when handling guest access to MSR_MISC_ENABLE

ISSUE DESCRIPTION When a guest accesses certain Model Specific Registers, Xen first reads the value from hardware to use as the basis for auditing the guest access. For the MISCENABLE MSR, which is an Intel specific MSR, this MSR read is performed without error handling for a GP fault, which is t...

Denial Of Service (DoS)

libvirt is vulnerable to denial of service DoS. The vulnerability exists as an issue was discovered in qemuDomainGetStatsIOThread in qemu/qemudriver.c in libvirt 4.10.0 though 6.x before 6.1.0. A memory leak was found in the virDomainListGetStats libvirt API that is responsible for retrieving...

Beers with Talos Ep. #87: Happy 3rd birthday BWT — It’s story time!

Beers with Talos BWT Podcast episode No. 87 is now available. Download this episode and subscribe to Beers with Talos:Apple Podcasts Google PodcastsSpotify StitcherIf iTunes and Google Play aren't your thing, click here. By Mitch Neff. Recorded June 24, 2020 Has it been three years already? We ha...

CVE-2020-15852

A flaw was found in the Linux kernel, in the way IOPL and IOPERM system calls were handled during context switches in x86 PV guests. This flaw allows a local guest user to escalate their privileges to the guest. The highest threat from this vulnerability is to data confidentiality and integrity a...

Xen Linux kernel privilege control vulnerability

Linux kernel is the kernel used by Linux, an open source operating system released by the Linux Foundation in the U.S. Xen is an open source virtual machine monitor product from the University of Cambridge, UK. The product enables different and incompatible operating systems to run on the same...

CVE-2020-15852

An issue was discovered in the Linux kernel 5.5 through 5.7.9, as used in Xen through 4.13.x for x86 PV guests. An attacker may be granted the I/O port permissions of an unrelated task. This occurs because tssinvalidateiobitmap mishandling causes a loss of synchronization between the I/O bitmaps ...

CVE-2020-15852: Incorrect Default Permissions

An issue was discovered in the Linux kernel 5.5 through 5.7.9, as used in Xen through 4.13.x for x86 PV guests. An attacker may be granted the I/O port permissions of an unrelated task. This occurs because tssinvalidateiobitmap mishandling causes a loss of synchronization between the I/O bitmaps ...

CVE-2020-15563

An issue was discovered in Xen through 4.13.x, allowing x86 HVM guest OS users to cause a hypervisor crash. An inverted conditional in x86 HVM guests' dirty video RAM tracking code allows such guests to make Xen de-reference a pointer guaranteed to point at unmapped space. A malicious or buggy HV...

Design/Logic Flaw

An issue was discovered in Xen through 4.13.x, allowing Intel guest OS users to gain privileges or cause a denial of service because of non-atomic modification of a live EPT PTE. When mapping guest EPT nested paging tables, Xen would in some circumstances use a series of non-atomic bitfield write...

CVE-2020-15563

An issue was discovered in Xen through 4.13.x, allowing x86 HVM guest OS users to cause a hypervisor crash. An inverted conditional in x86 HVM guests' dirty video RAM tracking code allows such guests to make Xen de-reference a pointer guaranteed to point at unmapped space. A malicious or buggy HV...

CVE-2020-15563

An issue was discovered in Xen through 4.13.x, allowing x86 HVM guest OS users to cause a hypervisor crash. An inverted conditional in x86 HVM guests' dirty video RAM tracking code allows such guests to make Xen de-reference a pointer guaranteed to point at unmapped space. A malicious or buggy HV...

insufficient cache write-back under VT-d

ISSUE DESCRIPTION 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 CPU cached also needs writing back to memory after changes were made. Such writing back of cached dat...

PT-2020-14494

Name of the Vulnerable Software and Affected Versions Xen versions 4.8 through 4.13.x Description An issue in Xen allows x86 HVM guest OS users to cause a hypervisor crash due to an inverted conditional in the dirty video RAM tracking code. This enables malicious or buggy HVM guests to make Xen...

microcode_ctl security, bug fix and enhancement update

2:2.1-61.6.0.1 - update 06-2d-07 to 0x71a - update 06-55-04 to 0x2006906 - update 06-55-07 to 0x5002f01 - for Intel, do not trigger load if on-disk microcode is not an update Orabug: 30634727 - set earlymicrocode='no' in virtualized guests to avoid early load bugs Orabug: 30618736 - do not late...

microcode_ctl security, bug fix and enhancement update

3:1.17-33.26.0.1 - update 06-2d-07 to 0x71a - update 06-55-04 to 0x2006906 - update 06-55-07 to 0x5002f01 - merge Oracle changes for early load via dracut - enable late load on install for UEK4 kernels marked safe except BDW-79 - set earlymicrocode='no' in virtualized guests to avoid early load...

EulerOS 2.0 SP2 : libguestfs-winsupport (EulerOS-SA-2020-1622)

According to the version of the libguestfs-winsupport package installed, the EulerOS installation on the remote host is affected by the following vulnerability : - This optional package adds support for Windows guests NTFS to the virt-v2v and virt-p2v programs.Security Fixes:An integer underflow...

Debian DSA-4698-1 : linux - security update

Several vulnerabilities have been discovered in the Linux kernel that may lead to a privilege escalation, denial of service or information leaks. - CVE-2019-2182 Hanjun Guo and Lei Li reported a race condition in the arm64 virtual memory management code, which could lead to an information...

CVE-2020-12430

An issue was discovered in qemuDomainGetStatsIOThread in qemu/qemudriver.c in libvirt 4.10.0 though 6.x before 6.1.0. A memory leak was found in the virDomainListGetStats libvirt API that is responsible for retrieving domain statistics when managing QEMU guests. This flaw allows unprivileged user...