CVSS: 5.5EPSS: 0%CPEs: 11EXPL: 0CVE-2020-27673
https://notcve.org/view.php?id=CVE-2020-27673
An issue was discovered in the Linux kernel through 5.9.1, as used with Xen through 4.14.x. Guest OS users can cause a denial of service (host OS hang) via a high rate of events to dom0, aka CID-e99502f76271. Se detectó un problema en el kernel de Linux versiones hasta 5.9.1, como es usado con Xen versiones hasta 4.14.x. Los usuarios del Sistema Operativo invitado pueden causar una denegación de servicio (suspensión del Sistema Operativo host) por medio de una alta tasa de eventos en dom0, también se conoce como CID-e99502f76271 • http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00075.html http://lists.opensuse.org/opensuse-security-announce/2020-11/msg00025.html http://www.openwall.com/lists/oss-security/2021/01/19/6 https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=e99502f76271d6bc4e374fe368c50c67a1fd3070 https://github.com/torvalds/linux/commit/e99502f76271d6bc4e374fe368c50c67a1fd3070 https://lists.debian.org/debian-lts-announce/2020/12/msg00015.html https://lists.debian.org/debian-lts-announ •
CVSS: 5.3EPSS: 0%CPEs: 5EXPL: 0CVE-2020-27674
https://notcve.org/view.php?id=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. Se detectó un problema en Xen versiones hasta 4.14.x, permitiendo a usuarios de SO invitado de PV x86 alcanzar privilegios de SO invitado modificando el contenido de la memoria del kernel, porque una invalidación de las entradas TLB es manejada inapropiadamente durante el uso de una técnica de ataque similar a INVLPG • http://www.openwall.com/lists/oss-security/2021/01/19/5 https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PZAM3LYJ5TZLSSNL3KXFILM46QKVTOUA https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/U3U4LNKKXU4UP4Z5XP6TMIWSML3QODPE https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XIK57QJOVOPWH6RFRNMGOBCROBCKMDG2 https://security.gentoo.org/glsa/202011-06 https://www.debian.org/security/2020/dsa-4804 https:/&#x • CWE-787: Out-of-bounds Write •
CVSS: 7.8EPSS: 0%CPEs: 6EXPL: 0CVE-2020-25603
https://notcve.org/view.php?id=CVE-2020-25603
An issue was discovered in Xen through 4.14.x. There are missing memory barriers when accessing/allocating an event channel. Event channels control structures can be accessed lockless as long as the port is considered to be valid. Such a sequence is missing an appropriate memory barrier (e.g., smp_*mb()) to prevent both the compiler and CPU from re-ordering access. A malicious guest may be able to cause a hypervisor crash resulting in a Denial of Service (DoS). • http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00008.html https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4JRXMKEMQRQYWYEPHVBIWUEAVQ3LU4FN https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DA633Y3G5KX7MKRN4PFEGM3IVTJMBEOM https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RJZERRBJN6E6STDCHT4JHP4MI6TKBCJE https://security.gentoo.org/glsa/202011-06 https://www.debian.org/security/2020/dsa-4769 htt • CWE-670: Always-Incorrect Control Flow Implementation •
CVSS: 5.5EPSS: 0%CPEs: 6EXPL: 0CVE-2020-25596
https://notcve.org/view.php?id=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. This causes the guest kernel to observe a kernel-privilege #GP fault (typically fatal) rather than a user-privilege #GP fault (usually converted into SIGSEGV/etc.). Malicious or buggy userspace can crash the guest kernel, resulting in a VM Denial of Service. • http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00008.html https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4JRXMKEMQRQYWYEPHVBIWUEAVQ3LU4FN https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DA633Y3G5KX7MKRN4PFEGM3IVTJMBEOM https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RJZERRBJN6E6STDCHT4JHP4MI6TKBCJE https://security.gentoo.org/glsa/202011-06 https://www.debian.org/security/2020/dsa-4769 htt • CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection') •
CVSS: 4.7EPSS: 0%CPEs: 6EXPL: 0CVE-2020-25604
https://notcve.org/view.php?id=CVE-2020-25604
An issue was discovered in Xen through 4.14.x. There is a race condition when migrating timers between x86 HVM vCPUs. When migrating timers of x86 HVM guests between its vCPUs, the locking model used allows for a second vCPU of the same guest (also operating on the timers) to release a lock that it didn't acquire. The most likely effect of the issue is a hang or crash of the hypervisor, i.e., a Denial of Service (DoS). All versions of Xen are affected. • http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00008.html https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4JRXMKEMQRQYWYEPHVBIWUEAVQ3LU4FN https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DA633Y3G5KX7MKRN4PFEGM3IVTJMBEOM https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RJZERRBJN6E6STDCHT4JHP4MI6TKBCJE https://security.gentoo.org/glsa/202011-06 https://www.debian.org/security/2020/dsa-4769 htt • CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') •