CVSS: 8.8EPSS: 0%CPEs: 4EXPL: 0CVE-2020-29479
https://notcve.org/view.php?id=CVE-2020-29479
An issue was discovered in Xen through 4.14.x. In the Ocaml xenstored implementation, the internal representation of the tree has special cases for the root node, because this node has no parent. Unfortunately, permissions were not checked for certain operations on the root node. Unprivileged guests can get and modify permissions, list, and delete the root node. (Deleting the whole xenstore tree is a host-wide denial of service.) • https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2C6M6S3CIMEBACH6O7V4H2VDANMO6TVA https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OBLV6L6Q24PPQ2CRFXDX4Q76KU776GKI https://security.gentoo.org/glsa/202107-30 https://www.debian.org/security/2020/dsa-4812 https://xenbits.xenproject.org/xsa/advisory-353.html • CWE-862: Missing Authorization •
CVSS: 8.8EPSS: 0%CPEs: 15EXPL: 0CVE-2020-29569
https://notcve.org/view.php?id=CVE-2020-29569
An issue was discovered in the Linux kernel through 5.10.1, as used with Xen through 4.14.x. The Linux kernel PV block backend expects the kernel thread handler to reset ring->xenblkd to NULL when stopped. However, the handler may not have time to run if the frontend quickly toggles between the states connect and disconnect. As a consequence, the block backend may re-use a pointer after it was freed. A misbehaving guest can trigger a dom0 crash by continuously connecting / disconnecting a block frontend. • https://lists.debian.org/debian-lts-announce/2021/02/msg00018.html https://lists.debian.org/debian-lts-announce/2021/03/msg00010.html https://security.gentoo.org/glsa/202107-30 https://security.netapp.com/advisory/ntap-20210205-0001 https://www.debian.org/security/2021/dsa-4843 https://xenbits.xenproject.org/xsa/advisory-350.html • CWE-416: Use After Free •
CVSS: 6.5EPSS: 0%CPEs: 3EXPL: 0CVE-2020-29568
https://notcve.org/view.php?id=CVE-2020-29568
An issue was discovered in Xen through 4.14.x. Some OSes (such as Linux, FreeBSD, and NetBSD) are processing watch events using a single thread. If the events are received faster than the thread is able to handle, they will get queued. As the queue is unbounded, a guest may be able to trigger an OOM in the backend. All systems with a FreeBSD, Linux, or NetBSD (any version) dom0 are vulnerable. • https://lists.debian.org/debian-lts-announce/2021/02/msg00018.html https://lists.debian.org/debian-lts-announce/2021/03/msg00010.html https://security.gentoo.org/glsa/202107-30 https://www.debian.org/security/2021/dsa-4843 https://xenbits.xenproject.org/xsa/advisory-349.html • CWE-770: Allocation of Resources Without Limits or Throttling •
CVSS: 6.2EPSS: 0%CPEs: 2EXPL: 0CVE-2020-29567
https://notcve.org/view.php?id=CVE-2020-29567
An issue was discovered in Xen 4.14.x. When moving IRQs between CPUs to distribute the load of IRQ handling, IRQ vectors are dynamically allocated and de-allocated on the relevant CPUs. De-allocation has to happen when certain constraints are met. If these conditions are not met when first checked, the checking CPU may send an interrupt to itself, in the expectation that this IRQ will be delivered only after the condition preventing the cleanup has cleared. For two specific IRQ vectors, this expectation was violated, resulting in a continuous stream of self-interrupts, which renders the CPU effectively unusable. • https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OBLV6L6Q24PPQ2CRFXDX4Q76KU776GKI https://security.gentoo.org/glsa/202107-30 https://xenbits.xenproject.org/xsa/advisory-356.html • CWE-770: Allocation of Resources Without Limits or Throttling •
CVSS: 5.5EPSS: 0%CPEs: 4EXPL: 0CVE-2020-29566
https://notcve.org/view.php?id=CVE-2020-29566
An issue was discovered in Xen through 4.14.x. When they require assistance from the device model, x86 HVM guests must be temporarily de-scheduled. The device model will signal Xen when it has completed its operation, via an event channel, so that the relevant vCPU is rescheduled. If the device model were to signal Xen without having actually completed the operation, the de-schedule / re-schedule cycle would repeat. If, in addition, Xen is resignalled very quickly, the re-schedule may occur before the de-schedule was fully complete, triggering a shortcut. • https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2C6M6S3CIMEBACH6O7V4H2VDANMO6TVA https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OBLV6L6Q24PPQ2CRFXDX4Q76KU776GKI https://security.gentoo.org/glsa/202107-30 https://www.debian.org/security/2020/dsa-4812 https://xenbits.xenproject.org/xsa/advisory-348.html • CWE-674: Uncontrolled Recursion •