CVSS: 7.8EPSS: 0%CPEs: 6EXPL: 0CVE-2020-15567
https://notcve.org/view.php?id=CVE-2020-15567
An issue was discovered in Xen through 4.13.x, allowing Intel guest OS users to gain privileges or cause a denial of service because of non-atomic modification of a live EPT PTE. When mapping guest EPT (nested paging) tables, Xen would in some circumstances use a series of non-atomic bitfield writes. Depending on the compiler version and optimisation flags, Xen might expose a dangerous partially written PTE to the hardware, which an attacker might be able to race to exploit. A guest administrator or perhaps even an unprivileged guest user might be able to cause denial of service, data corruption, or privilege escalation. Only systems using Intel CPUs are vulnerable. • http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00024.html http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00031.html http://www.openwall.com/lists/oss-security/2020/07/07/6 http://xenbits.xen.org/xsa/advisory-328.html https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MXESCOVI7AVRNC7HEAMFM7PMEO6D3AUH https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VB3QJJZV23Z2IDYEMIHELWYSQBUEW6JP https://security.ge • CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') •
CVSS: 6.5EPSS: 0%CPEs: 4EXPL: 0CVE-2020-15564
https://notcve.org/view.php?id=CVE-2020-15564
An issue was discovered in Xen through 4.13.x, allowing Arm guest OS users to cause a hypervisor crash because of a missing alignment check in VCPUOP_register_vcpu_info. The hypercall VCPUOP_register_vcpu_info is used by a guest to register a shared region with the hypervisor. The region will be mapped into Xen address space so it can be directly accessed. On Arm, the region is accessed with instructions that require a specific alignment. Unfortunately, there is no check that the address provided by the guest will be correctly aligned. • http://www.openwall.com/lists/oss-security/2020/07/07/5 http://xenbits.xen.org/xsa/advisory-327.html https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MXESCOVI7AVRNC7HEAMFM7PMEO6D3AUH https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VB3QJJZV23Z2IDYEMIHELWYSQBUEW6JP https://security.gentoo.org/glsa/202007-02 https://www.debian.org/security/2020/dsa-4723 • CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer •
CVSS: 8.8EPSS: 0%CPEs: 6EXPL: 0CVE-2020-15565
https://notcve.org/view.php?id=CVE-2020-15565
An issue was discovered in Xen through 4.13.x, allowing x86 Intel HVM guest OS users to cause a host OS denial of service or possibly gain privileges because of insufficient cache write-back under VT-d. When page tables are shared between IOMMU and CPU, changes to them require flushing of both TLBs. Furthermore, IOMMUs may be non-coherent, and hence prior to flushing IOMMU TLBs, a CPU cache also needs writing back to memory after changes were made. Such writing back of cached data was missing in particular when splitting large page mappings into smaller granularity ones. A malicious guest may be able to retain read/write DMA access to frames returned to Xen's free pool, and later reused for another purpose. • http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00024.html http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00031.html http://www.openwall.com/lists/oss-security/2020/07/07/4 http://xenbits.xen.org/xsa/advisory-321.html https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MXESCOVI7AVRNC7HEAMFM7PMEO6D3AUH https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VB3QJJZV23Z2IDYEMIHELWYSQBUEW6JP https://security.ge • CWE-400: Uncontrolled Resource Consumption •
CVSS: 6.5EPSS: 0%CPEs: 5EXPL: 0CVE-2020-15563
https://notcve.org/view.php?id=CVE-2020-15563
An issue was discovered in Xen through 4.13.x, allowing x86 HVM guest OS users to cause a hypervisor crash. An inverted conditional in x86 HVM guests' dirty video RAM tracking code allows such guests to make Xen de-reference a pointer guaranteed to point at unmapped space. A malicious or buggy HVM guest may cause the hypervisor to crash, resulting in Denial of Service (DoS) affecting the entire host. Xen versions from 4.8 onwards are affected. Xen versions 4.7 and earlier are not affected. • http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00024.html http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00031.html http://www.openwall.com/lists/oss-security/2020/07/07/3 http://xenbits.xen.org/xsa/advisory-319.html https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MXESCOVI7AVRNC7HEAMFM7PMEO6D3AUH https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VB3QJJZV23Z2IDYEMIHELWYSQBUEW6JP https://security.ge • CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer •
CVSS: 6.5EPSS: 0%CPEs: 2EXPL: 0CVE-2020-15566
https://notcve.org/view.php?id=CVE-2020-15566
An issue was discovered in Xen through 4.13.x, allowing guest OS users to cause a host OS crash because of incorrect error handling in event-channel port allocation. The allocation of an event-channel port may fail for multiple reasons: (1) port is already in use, (2) the memory allocation failed, or (3) the port we try to allocate is higher than what is supported by the ABI (e.g., 2L or FIFO) used by the guest or the limit set by an administrator (max_event_channels in xl cfg). Due to the missing error checks, only (1) will be considered an error. All the other cases will provide a valid port and will result in a crash when trying to access the event channel. When the administrator configured a guest to allow more than 1023 event channels, that guest may be able to crash the host. • http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00024.html http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00031.html http://www.openwall.com/lists/oss-security/2020/07/07/2 http://xenbits.xen.org/xsa/advisory-317.html https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MXESCOVI7AVRNC7HEAMFM7PMEO6D3AUH https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VB3QJJZV23Z2IDYEMIHELWYSQBUEW6JP https://security.ge • CWE-754: Improper Check for Unusual or Exceptional Conditions •