CVSS: 8.8EPSS: 0%CPEs: 2EXPL: 0CVE-2019-19578
https://notcve.org/view.php?id=CVE-2019-19578
An issue was discovered in Xen through 4.12.x allowing x86 PV guest OS users to cause a denial of service via degenerate chains of linear pagetables, because of an incorrect fix for CVE-2017-15595. "Linear pagetables" is a technique which involves either pointing a pagetable at itself, or to another pagetable of the same or higher level. Xen has limited support for linear pagetables: A page may either point to itself, or point to another pagetable of the same level (i.e., L2 to L2, L3 to L3, and so on). XSA-240 introduced an additional restriction that limited the "depth" of such chains by allowing pages to either *point to* other pages of the same level, or *be pointed to* by other pages of the same level, but not both. To implement this, we keep track of the number of outstanding times a page points to or is pointed to another page table, to prevent both from happening at the same time. • http://lists.opensuse.org/opensuse-security-announce/2020-01/msg00011.html https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/34HBFTYNMQMWIO2GGK7DB6KV4M6R5YPV https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/D5R73AYE53QA32KTMHUVKCX6E52CIS43 https://seclists.org/bugtraq/2020/Jan/21 https://security.gentoo.org/glsa/202003-56 https://www.debian.org/security/2020/dsa-4602 https://xenbits.xen.org/xsa/advisory-309.html • CWE-682: Incorrect Calculation •
CVSS: 6.6EPSS: 0%CPEs: 2EXPL: 0CVE-2019-19580
https://notcve.org/view.php?id=CVE-2019-19580
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, because of an incomplete fix for CVE-2019-18421. XSA-299 addressed several critical issues in restartable PV type change operations. Despite extensive testing and auditing, some corner cases were missed. A malicious PV guest administrator may be able to escalate their privilege to that of the host. All security-supported versions of Xen are vulnerable. • http://lists.opensuse.org/opensuse-security-announce/2020-01/msg00011.html https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/34HBFTYNMQMWIO2GGK7DB6KV4M6R5YPV https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/D5R73AYE53QA32KTMHUVKCX6E52CIS43 https://seclists.org/bugtraq/2020/Jan/21 https://security.gentoo.org/glsa/202003-56 https://www.debian.org/security/2020/dsa-4602 https://xenbits.xen.org/xsa/advisory-310.html • CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') •
CVSS: 7.2EPSS: 0%CPEs: 2EXPL: 0CVE-2019-19579
https://notcve.org/view.php?id=CVE-2019-19579
An issue was discovered in Xen through 4.12.x allowing attackers to gain host OS privileges via DMA in a situation where an untrusted domain has access to a physical device (and assignable-add is not used), because of an incomplete fix for CVE-2019-18424. XSA-302 relies on the use of libxl's "assignable-add" feature to prepare devices to be assigned to untrusted guests. Unfortunately, this is not considered a strictly required step for device assignment. The PCI passthrough documentation on the wiki describes alternate ways of preparing devices for assignment, and libvirt uses its own ways as well. Hosts where these "alternate" methods are used will still leave the system in a vulnerable state after the device comes back from a guest. • http://lists.opensuse.org/opensuse-security-announce/2020-01/msg00011.html http://www.openwall.com/lists/oss-security/2019/12/05/7 http://xenbits.xen.org/xsa/advisory-306.html https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RJYT5FNGM7JSVHHW6B22TSAATBOAPFPD https://seclists.org/bugtraq/2020/Jan/21 https://www.debian.org/security/2020/dsa-4602 https://www.openwall.com/lists/oss-security/2019/11/26/2 https://xenbits.xen.org/xsa/advisory-30 • CWE-20: Improper Input Validation •
CVSS: 9.8EPSS: 1%CPEs: 7EXPL: 0CVE-2019-18425
https://notcve.org/view.php?id=CVE-2019-18425
An issue was discovered in Xen through 4.12.x allowing 32-bit PV guest OS users to gain guest OS privileges by installing and using descriptors. There is missing descriptor table limit checking in x86 PV emulation. When emulating certain PV guest operations, descriptor table accesses are performed by the emulating code. Such accesses should respect the guest specified limits, unless otherwise guaranteed to fail in such a case. Without this, emulation of 32-bit guest user mode calls through call gates would allow guest user mode to install and then use descriptors of their choice, as long as the guest kernel did not itself install an LDT. • http://lists.opensuse.org/opensuse-security-announce/2019-11/msg00037.html http://www.openwall.com/lists/oss-security/2019/10/31/2 http://xenbits.xen.org/xsa/advisory-298.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-269: Improper Privilege Management •
CVSS: 6.9EPSS: 0%CPEs: 7EXPL: 0CVE-2019-18424
https://notcve.org/view.php?id=CVE-2019-18424
An issue was discovered in Xen through 4.12.x allowing attackers to gain host OS privileges via DMA in a situation where an untrusted domain has access to a physical device. This occurs because passed through PCI devices may corrupt host memory after deassignment. When a PCI device is assigned to an untrusted domain, it is possible for that domain to program the device to DMA to an arbitrary address. The IOMMU is used to protect the host from malicious DMA by making sure that the device addresses can only target memory assigned to the guest. However, when the guest domain is torn down, or the device is deassigned, the device is assigned back to dom0, thus allowing any in-flight DMA to potentially target critical host data. • http://lists.opensuse.org/opensuse-security-announce/2019-11/msg00037.html http://www.openwall.com/lists/oss-security/2019/10/31/6 http://xenbits.xen.org/xsa/advisory-302.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-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') •