CVSS: 7.0EPSS: 0%CPEs: 1EXPL: 0CVE-2021-28703
https://notcve.org/view.php?id=CVE-2021-28703
grant table v2 status pages may remain accessible after de-allocation (take two) Guest get permitted access to certain Xen-owned pages of memory. The majority of such pages remain allocated / associated with a guest for its entire lifetime. Grant table v2 status pages, however, get de-allocated when a guest switched (back) from v2 to v1. The freeing of such pages requires that the hypervisor know where in the guest these pages were mapped. The hypervisor tracks only one use within guest space, but racing requests from the guest to insert mappings of these pages may result in any of them to become mapped in multiple locations. • https://security.gentoo.org/glsa/202402-07 https://xenbits.xenproject.org/xsa/advisory-387.txt •
CVSS: 8.8EPSS: 0%CPEs: 4EXPL: 0CVE-2021-28704
https://notcve.org/view.php?id=CVE-2021-28704
PoD operations on misaligned GFNs T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] x86 HVM and PVH guests may be started in populate-on-demand (PoD) mode, to provide a way for them to later easily have more memory assigned. Guests are permitted to control certain P2M aspects of individual pages via hypercalls. These hypercalls may act on ranges of pages specified via page orders (resulting in a power-of-2 number of pages). The implementation of some of these hypercalls for PoD does not enforce the base page frame number to be suitably aligned for the specified order, yet some code involved in PoD handling actually makes such an assumption. These operations are XENMEM_decrease_reservation (CVE-2021-28704) and XENMEM_populate_physmap (CVE-2021-28707), the latter usable only by domains controlling the guest, i.e. a de-privileged qemu or a stub domain. • https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/I7ZGWVVRI4XY2XSTBI3XEMWBXPDVX6OT https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PXUI4VMD52CH3T7YXAG3J2JW7ZNN3SXF https://security.gentoo.org/glsa/202402-07 https://www.debian.org/security/2021/dsa-5017 https://xenbits.xenproject.org/xsa/advisory-388.txt •
CVSS: 7.8EPSS: 0%CPEs: 8EXPL: 0CVE-2021-28705
https://notcve.org/view.php?id=CVE-2021-28705
issues with partially successful P2M updates on x86 T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] x86 HVM and PVH guests may be started in populate-on-demand (PoD) mode, to provide a way for them to later easily have more memory assigned. Guests are permitted to control certain P2M aspects of individual pages via hypercalls. These hypercalls may act on ranges of pages specified via page orders (resulting in a power-of-2 number of pages). In some cases the hypervisor carries out the requests by splitting them into smaller chunks. Error handling in certain PoD cases has been insufficient in that in particular partial success of some operations was not properly accounted for. • https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/I7ZGWVVRI4XY2XSTBI3XEMWBXPDVX6OT https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PXUI4VMD52CH3T7YXAG3J2JW7ZNN3SXF https://security.gentoo.org/glsa/202402-07 https://www.debian.org/security/2021/dsa-5017 https://xenbits.xenproject.org/xsa/advisory-389.txt • CWE-755: Improper Handling of Exceptional Conditions •
CVSS: 8.6EPSS: 0%CPEs: 4EXPL: 0CVE-2021-28706
https://notcve.org/view.php?id=CVE-2021-28706
guests may exceed their designated memory limit When a guest is permitted to have close to 16TiB of memory, it may be able to issue hypercalls to increase its memory allocation beyond the administrator established limit. This is a result of a calculation done with 32-bit precision, which may overflow. It would then only be the overflowed (and hence small) number which gets compared against the established upper bound. Los huéspedes pueden exceder su límite de memoria designado Cuando a un huésped se le permite tener cerca de 16TiB de memoria, puede ser capaz de emitir hypercalls para aumentar su asignación de memoria más allá del límite establecido por el administrador. Esto es el resultado de un cálculo realizado con precisión de 32 bits, que puede desbordarse. • https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/I7ZGWVVRI4XY2XSTBI3XEMWBXPDVX6OT https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PXUI4VMD52CH3T7YXAG3J2JW7ZNN3SXF https://security.gentoo.org/glsa/202402-07 https://www.debian.org/security/2021/dsa-5017 https://xenbits.xenproject.org/xsa/advisory-385.txt • CWE-770: Allocation of Resources Without Limits or Throttling •
CVSS: 8.8EPSS: 0%CPEs: 4EXPL: 0CVE-2021-28707
https://notcve.org/view.php?id=CVE-2021-28707
PoD operations on misaligned GFNs T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] x86 HVM and PVH guests may be started in populate-on-demand (PoD) mode, to provide a way for them to later easily have more memory assigned. Guests are permitted to control certain P2M aspects of individual pages via hypercalls. These hypercalls may act on ranges of pages specified via page orders (resulting in a power-of-2 number of pages). The implementation of some of these hypercalls for PoD does not enforce the base page frame number to be suitably aligned for the specified order, yet some code involved in PoD handling actually makes such an assumption. These operations are XENMEM_decrease_reservation (CVE-2021-28704) and XENMEM_populate_physmap (CVE-2021-28707), the latter usable only by domains controlling the guest, i.e. a de-privileged qemu or a stub domain. • https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/I7ZGWVVRI4XY2XSTBI3XEMWBXPDVX6OT https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PXUI4VMD52CH3T7YXAG3J2JW7ZNN3SXF https://security.gentoo.org/glsa/202402-07 https://www.debian.org/security/2021/dsa-5017 https://xenbits.xenproject.org/xsa/advisory-388.txt •