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: 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: 5.5EPSS: 0%CPEs: 4EXPL: 2CVE-2020-11743
https://notcve.org/view.php?id=CVE-2020-11743
An issue was discovered in Xen through 4.13.x, allowing guest OS users to cause a denial of service because of a bad error path in GNTTABOP_map_grant. Grant table operations are expected to return 0 for success, and a negative number for errors. Some misplaced brackets cause one error path to return 1 instead of a negative value. The grant table code in Linux treats this condition as success, and proceeds with incorrectly initialised state. A buggy or malicious guest can construct its grant table in such a way that, when a backend domain tries to map a grant, it hits the incorrect error path. • http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00006.html http://www.openwall.com/lists/oss-security/2020/04/14/3 http://xenbits.xen.org/xsa/advisory-316.html https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5M2XRNCHOGGTJQBZQJ7DCV6ZNAKN3LE2 https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NVTP4OYHCTRU3ONFJOFJQVNDFB25KLLG https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YMAW7D2MP • CWE-755: Improper Handling of Exceptional Conditions •
CVSS: 5.5EPSS: 0%CPEs: 4EXPL: 0CVE-2020-11742
https://notcve.org/view.php?id=CVE-2020-11742
An issue was discovered in Xen through 4.13.x, allowing guest OS users to cause a denial of service because of bad continuation handling in GNTTABOP_copy. Grant table operations are expected to return 0 for success, and a negative number for errors. The fix for CVE-2017-12135 introduced a path through grant copy handling where success may be returned to the caller without any action taken. In particular, the status fields of individual operations are left uninitialised, and may result in errant behaviour in the caller of GNTTABOP_copy. A buggy or malicious guest can construct its grant table in such a way that, when a backend domain tries to copy a grant, it hits the incorrect exit path. • http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00006.html http://www.openwall.com/lists/oss-security/2020/04/14/4 http://xenbits.xen.org/xsa/advisory-318.html https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5M2XRNCHOGGTJQBZQJ7DCV6ZNAKN3LE2 https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NVTP4OYHCTRU3ONFJOFJQVNDFB25KLLG https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YMAW7D2MP •
CVSS: 8.8EPSS: 0%CPEs: 8EXPL: 0CVE-2020-11741
https://notcve.org/view.php?id=CVE-2020-11741
An issue was discovered in xenoprof in Xen through 4.13.x, allowing guest OS users (with active profiling) to obtain sensitive information about other guests, cause a denial of service, or possibly gain privileges. For guests for which "active" profiling was enabled by the administrator, the xenoprof code uses the standard Xen shared ring structure. Unfortunately, this code did not treat the guest as a potential adversary: it trusts the guest not to modify buffer size information or modify head / tail pointers in unexpected ways. This can crash the host (DoS). Privilege escalation cannot be ruled out. • http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00006.html http://www.openwall.com/lists/oss-security/2020/04/14/1 http://xenbits.xen.org/xsa/advisory-313.html https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5M2XRNCHOGGTJQBZQJ7DCV6ZNAKN3LE2 https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NVTP4OYHCTRU3ONFJOFJQVNDFB25KLLG https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YMAW7D2MP • CWE-909: Missing Initialization of Resource •