Xenstore: guests can disturb domain cleanup

ISSUE DESCRIPTION Xenstored and guests communicate via a shared memory page using a specific protocol. When a guest violates this protocol, xenstored will drop the connection to that guest. Unfortunately this is done by just removing the guest from xenstored's internal management, resulting in th...

SUSE SLED15 / SLES15 Security Update : qemu (SUSE-SU-2020:2877-1)

This update for qemu fixes the following issues : CVE-2020-14364: Fixed an OOB access while processing USB packets bsc1175441,bsc1176494. CVE-2020-16092: Fixed a denial of service in packet processing of various emulated NICs bsc1174641. CVE-2020-15863: Fixed a buffer overflow in the XGMAC device...

CVE-2020-29040

An off-by-one flaw was found in one of the two patches for CVE-2020-27671 XSA-346. This flaw allows malicious x86 HVM and PVH guests to cause host data corruption and data leaks, resulting in a denial of service or potential privilege escalation. The highest threat from this vulnerability is to...

DEBIAN-CVE-2020-29040

An issue was discovered in Xen through 4.14.x allowing x86 HVM guest OS users to cause a denial of service stack corruption, cause a data leak, or possibly gain privileges because of an off-by-one error. NOTE: this issue is caused by an incorrect fix for CVE-2020-27671...

stack corruption from XSA-346 change

ISSUE DESCRIPTION One of the two changes for XSA-346 introduced an on-stack array. The check for guarding against overrunning this array was off by one, allowing for corruption of the first stack slot immediately following this array. IMPACT A malicious or buggy HVM or PVH guest can cause Xen to...

libvirt: leak of /dev/mapper/control into QEMU guests

A flaw was found in libvirt, where it leaked a file descriptor for /dev/mapper/control into the QEMU process. This file descriptor allows for privileged operations to happen against the device-mapper on the host. This flaw allows a malicious guest user or process to perform operations outside of...

CVE-2020-27670

A flaw was found in Xen in the AMD IOMMU page table updates. This flaw allows a malicious guest to cause a denial of service, host data corruption, or potential privilege escalation. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability...

Xen Migrating Timers Race condition DoS (XSA-336)

According to its self-reported version number, the Xen hypervisor installed on the remote host is affected by a denial of service DoS vulnerability. When migrating timers of x86 HVM guests between its vCPU-s, the locking model used allows for a second vCPU of the same guest also operating on the...

UBUNTU-CVE-2020-27674

An issue was discovered in Xen through 4.14.x allowing x86 PV guest OS users to gain guest OS privileges by modifying kernel memory contents, because invalidation of TLB entries is mishandled during use of an INVLPG-like attack technique...

Rogue guests can cause DoS of Dom0 via high frequency events

ISSUE DESCRIPTION The handling of Xen events in the Linux kernel runs with interrupts disabled in a loop until no further event is pending. Whenever an event has been accepted by the kernel, another event can come in via the same event channel. This can result in the event handling loop running f...

undue deferral of IOMMU TLB flushes

ISSUE DESCRIPTION To efficiently change the physical to machine address mappings of a larger range of addresses for fully virtualized guests, Xen contains an optimization to coalesce per-page IOMMU TLB flushes into a single, wider flush after all adjustments have been made. While this is fine to ...

CVE-2020-25602

An issue was discovered in Xen through 4.14.x. An x86 PV guest can trigger a host OS crash when handling guest access to MSRMISCENABLE. 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...

ALPINE-CVE-2020-25596

An issue was discovered in Xen through 4.14.x. x86 PV guest kernels can experience denial of service via SYSENTER. The SYSENTER instruction leaves various state sanitization activities to software. One of Xen's sanitization paths injects a GP fault, and incorrectly delivers it twice to the guest...

DEBIAN-CVE-2020-25596

An issue was discovered in Xen through 4.14.x. x86 PV guest kernels can experience denial of service via SYSENTER. The SYSENTER instruction leaves various state sanitization activities to software. One of Xen's sanitization paths injects a GP fault, and incorrectly delivers it twice to the guest...

DEBIAN-CVE-2020-25597

An issue was discovered in Xen through 4.14.x. There is mishandling of the constraint that once-valid event channels may not turn invalid. Logic in the handling of event channel operations in Xen assumes that an event channel, once valid, will not become invalid over the life time of a guest...

CVE-2020-25602

An issue was discovered in Xen through 4.14.x. An x86 PV guest can trigger a host OS crash when handling guest access to MSRMISCENABLE. 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...

ALPINE-CVE-2020-25597

An issue was discovered in Xen through 4.14.x. There is mishandling of the constraint that once-valid event channels may not turn invalid. Logic in the handling of event channel operations in Xen assumes that an event channel, once valid, will not become invalid over the life time of a guest...

CVE-2020-25597

An issue was discovered in Xen through 4.14.x. There is mishandling of the constraint that once-valid event channels may not turn invalid. Logic in the handling of event channel operations in Xen assumes that an event channel, once valid, will not become invalid over the life time of a guest...

UBUNTU-CVE-2020-25597

An issue was discovered in Xen through 4.14.x. There is mishandling of the constraint that once-valid event channels may not turn invalid. Logic in the handling of event channel operations in Xen assumes that an event channel, once valid, will not become invalid over the life time of a guest...

UBUNTU-CVE-2020-25596

An issue was discovered in Xen through 4.14.x. x86 PV guest kernels can experience denial of service via SYSENTER. The SYSENTER instruction leaves various state sanitization activities to software. One of Xen's sanitization paths injects a GP fault, and incorrectly delivers it twice to the guest...