CVSS: 7.5EPSS: 0%CPEs: 7EXPL: 0CVE-2019-18421
https://notcve.org/view.php?id=CVE-2019-18421
An issue was discovered in Xen through 4.12.x allowing x86 PV guest OS users to gain host OS privileges by leveraging race conditions in pagetable promotion and demotion operations. There are issues with restartable PV type change operations. To avoid using shadow pagetables for PV guests, Xen exposes the actual hardware pagetables to the guest. In order to prevent the guest from modifying these page tables directly, Xen keeps track of how pages are used using a type system; pages must be "promoted" before being used as a pagetable, and "demoted" before being used for any other type. Xen also allows for "recursive" promotions: i.e., an operating system promoting a page to an L4 pagetable may end up causing pages to be promoted to L3s, which may in turn cause pages to be promoted to L2s, and so on. • http://lists.opensuse.org/opensuse-security-announce/2019-11/msg00037.html http://www.openwall.com/lists/oss-security/2019/10/31/3 http://xenbits.xen.org/xsa/advisory-299.html https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2BQKX7M2RHCWDBKNPX4KEBI3MJIH6AYZ https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/I5WWPW4BSZDDW7VHU427XTVXV7ROOFFW https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IZYATWNUG • CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') •
CVSS: 6.5EPSS: 1%CPEs: 6EXPL: 0CVE-2019-18420
https://notcve.org/view.php?id=CVE-2019-18420
An issue was discovered in Xen through 4.12.x allowing x86 PV guest OS users to cause a denial of service via a VCPUOP_initialise hypercall. hypercall_create_continuation() is a variadic function which uses a printf-like format string to interpret its parameters. Error handling for a bad format character was done using BUG(), which crashes Xen. One path, via the VCPUOP_initialise hypercall, has a bad format character. The BUG() can be hit if VCPUOP_initialise executes for a sufficiently long period of time for a continuation to be created. Malicious guests may cause a hypervisor crash, resulting in a Denial of Service (DoS). • http://lists.opensuse.org/opensuse-security-announce/2019-11/msg00037.html http://www.openwall.com/lists/oss-security/2019/10/31/1 http://xenbits.xen.org/xsa/advisory-296.html https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2BQKX7M2RHCWDBKNPX4KEBI3MJIH6AYZ https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/I5WWPW4BSZDDW7VHU427XTVXV7ROOFFW https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IZYATWNUG • CWE-134: Use of Externally-Controlled Format String •
CVSS: 8.8EPSS: 0%CPEs: 3EXPL: 0CVE-2019-17340
https://notcve.org/view.php?id=CVE-2019-17340
An issue was discovered in Xen through 4.11.x allowing x86 guest OS users to cause a denial of service or gain privileges because grant-table transfer requests are mishandled. Se detectó un problema en Xen versiones hasta 4.11.x, permitiendo a usuarios del sistema operativo invitado de x86, causar una denegación de servicio u alcanzar privilegios porque las peticiones de transferencia grant-table son manejadas inapropiadamente. • http://www.openwall.com/lists/oss-security/2019/10/25/1 http://xenbits.xen.org/xsa/advisory-284.html https://seclists.org/bugtraq/2020/Jan/21 https://www.debian.org/security/2020/dsa-4602 https://xenbits.xen.org/xsa/advisory-284.html • CWE-401: Missing Release of Memory after Effective Lifetime •
CVSS: 7.8EPSS: 0%CPEs: 3EXPL: 0CVE-2019-17341
https://notcve.org/view.php?id=CVE-2019-17341
An issue was discovered in Xen through 4.11.x allowing x86 PV guest OS users to cause a denial of service or gain privileges by leveraging a page-writability race condition during addition of a passed-through PCI device. Se detectó un problema en Xen versiones hasta 4.11.x, permitiendo a usuarios del sistema operativo invitado PV de x86, causar una denegación de servicio u alcanzar privilegios mediante el aprovechamiento de una condición de carrera de escritura de página durante la adición de un dispositivo PCI transferido. • http://www.openwall.com/lists/oss-security/2019/10/25/6 http://xenbits.xen.org/xsa/advisory-285.html https://seclists.org/bugtraq/2020/Jan/21 https://www.debian.org/security/2020/dsa-4602 https://xenbits.xen.org/xsa/advisory-285.html • CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') •
CVSS: 7.0EPSS: 0%CPEs: 3EXPL: 0CVE-2019-17342
https://notcve.org/view.php?id=CVE-2019-17342
An issue was discovered in Xen through 4.11.x allowing x86 PV guest OS users to cause a denial of service or gain privileges by leveraging a race condition that arose when XENMEM_exchange was introduced. Se detectó un problema en Xen versiones hasta 4.11.x, permitiendo a usuarios del sistema operativo invitado PV de x86, causar una denegación de servicio u alcanzar privilegios mediante el aprovechamiento de una condición de carrera que surgió cuando se introdujo XENMEM_exchange. • http://www.openwall.com/lists/oss-security/2019/10/25/2 http://xenbits.xen.org/xsa/advisory-287.html https://seclists.org/bugtraq/2020/Jan/21 https://www.debian.org/security/2020/dsa-4602 https://xenbits.xen.org/xsa/advisory-287.html • CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') •