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. (Patch 1, combining the fix to both these two issues.) In addition handling of XENMEM_decrease_reservation can also trigger a host crash when the specified page order is neither 4k nor 2M nor 1G (CVE-2021-28708, patch 2).

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - 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.
    (Patch 1, combining the fix to both these two issues.) In addition handling of XENMEM_decrease_reservation     can also trigger a host crash when the specified page order is neither 4k nor 2M nor 1G (CVE-2021-28708,     patch 2). (CVE-2021-28707)

Note that Nessus relies on the presence of the package as reported by the vendor.

The remote host is affected by the vulnerability described in GLSA-202402-07 (Xen: Multiple Vulnerabilities)

    Multiple vulnerabilities have been discovered in Xen. Please review the CVE identifiers referenced below     for details.

Tenable has extracted the preceding description block directly from the Gentoo Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote SUSE Linux SLES15 / SLES_SAP15 host has packages installed that are affected by multiple vulnerabilities as referenced in the SUSE-SU-2021:3977-1 advisory.

  - Another race in XENMAPSPACE_grant_table handling Guests are 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, are de-allocated when a guest switches (back) from v2 to v1. Freeing     such pages requires that the hypervisor enforce that no parallel request can result in the addition of a     mapping of such a page to a guest. That enforcement was missing, allowing guests to retain access to pages     that were freed and perhaps re-used for other purposes. Unfortunately, when XSA-379 was being prepared,     this similar issue was not noticed. (CVE-2021-28701)

  - PCI devices with RMRRs not deassigned correctly Certain PCI devices in a system might be assigned Reserved     Memory Regions (specified via Reserved Memory Region Reporting, RMRR). These are typically used for     platform tasks such as legacy USB emulation. If such a device is passed through to a guest, then on guest     shutdown the device is not properly deassigned. The IOMMU configuration for these devices which are not     properly deassigned ends up pointing to a freed data structure, including the IO Pagetables. Subsequent     DMA or interrupts from the device will have unpredictable behaviour, ranging from IOMMU faults to memory     corruption. (CVE-2021-28702)

  - 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.
    (Patch 1, combining the fix to both these two issues.) In addition handling of XENMEM_decrease_reservation     can also trigger a host crash when the specified page order is neither 4k nor 2M nor 1G (CVE-2021-28708,     patch 2). (CVE-2021-28704, CVE-2021-28707, CVE-2021-28708)

  - 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. There are two code paths affected - page removal     (CVE-2021-28705) and insertion of new pages (CVE-2021-28709). (We provide one patch which combines the fix     to both issues.) (CVE-2021-28705, CVE-2021-28709)

  - 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. (CVE-2021-28706)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote SUSE Linux SUSE15 host has packages installed that are affected by multiple vulnerabilities as referenced in the openSUSE-SU-2021:3968-1 advisory.

  - PCI devices with RMRRs not deassigned correctly Certain PCI devices in a system might be assigned Reserved     Memory Regions (specified via Reserved Memory Region Reporting, RMRR). These are typically used for     platform tasks such as legacy USB emulation. If such a device is passed through to a guest, then on guest     shutdown the device is not properly deassigned. The IOMMU configuration for these devices which are not     properly deassigned ends up pointing to a freed data structure, including the IO Pagetables. Subsequent     DMA or interrupts from the device will have unpredictable behaviour, ranging from IOMMU faults to memory     corruption. (CVE-2021-28702)

  - 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.
    (Patch 1, combining the fix to both these two issues.) In addition handling of XENMEM_decrease_reservation     can also trigger a host crash when the specified page order is neither 4k nor 2M nor 1G (CVE-2021-28708,     patch 2). (CVE-2021-28704, CVE-2021-28707, CVE-2021-28708)

  - 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. There are two code paths affected - page removal     (CVE-2021-28705) and insertion of new pages (CVE-2021-28709). (We provide one patch which combines the fix     to both issues.) (CVE-2021-28705, CVE-2021-28709)

  - 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. (CVE-2021-28706)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote SUSE Linux SLED15 / SLES15 host has packages installed that are affected by multiple vulnerabilities as referenced in the SUSE-SU-2021:3968-1 advisory.

  - PCI devices with RMRRs not deassigned correctly Certain PCI devices in a system might be assigned Reserved     Memory Regions (specified via Reserved Memory Region Reporting, RMRR). These are typically used for     platform tasks such as legacy USB emulation. If such a device is passed through to a guest, then on guest     shutdown the device is not properly deassigned. The IOMMU configuration for these devices which are not     properly deassigned ends up pointing to a freed data structure, including the IO Pagetables. Subsequent     DMA or interrupts from the device will have unpredictable behaviour, ranging from IOMMU faults to memory     corruption. (CVE-2021-28702)

  - 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.
    (Patch 1, combining the fix to both these two issues.) In addition handling of XENMEM_decrease_reservation     can also trigger a host crash when the specified page order is neither 4k nor 2M nor 1G (CVE-2021-28708,     patch 2). (CVE-2021-28704, CVE-2021-28707, CVE-2021-28708)

  - 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. There are two code paths affected - page removal     (CVE-2021-28705) and insertion of new pages (CVE-2021-28709). (We provide one patch which combines the fix     to both issues.) (CVE-2021-28705, CVE-2021-28709)

  - 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. (CVE-2021-28706)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote SUSE Linux SUSE15 host has packages installed that are affected by multiple vulnerabilities as referenced in the openSUSE-SU-2021:1543-1 advisory.

  - PCI devices with RMRRs not deassigned correctly Certain PCI devices in a system might be assigned Reserved     Memory Regions (specified via Reserved Memory Region Reporting, RMRR). These are typically used for     platform tasks such as legacy USB emulation. If such a device is passed through to a guest, then on guest     shutdown the device is not properly deassigned. The IOMMU configuration for these devices which are not     properly deassigned ends up pointing to a freed data structure, including the IO Pagetables. Subsequent     DMA or interrupts from the device will have unpredictable behaviour, ranging from IOMMU faults to memory     corruption. (CVE-2021-28702)

  - 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.
    (Patch 1, combining the fix to both these two issues.) In addition handling of XENMEM_decrease_reservation     can also trigger a host crash when the specified page order is neither 4k nor 2M nor 1G (CVE-2021-28708,     patch 2). (CVE-2021-28704, CVE-2021-28707, CVE-2021-28708)

  - 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. There are two code paths affected - page removal     (CVE-2021-28705) and insertion of new pages (CVE-2021-28709). (We provide one patch which combines the fix     to both issues.) (CVE-2021-28705, CVE-2021-28709)

  - 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. (CVE-2021-28706)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote Debian 11 host has packages installed that are affected by multiple vulnerabilities as referenced in the dsa-5017 advisory.

    Multiple vulnerabilities have been discovered in the Xen hypervisor, which could result in privilege     escalation, denial of service or information leaks. For the stable distribution (bullseye), these problems     have been fixed in version 4.14.3+32-g9de3671772-1~deb11u1. We recommend that you upgrade your xen     packages. For the detailed security status of xen please refer to its security tracker page at:
    https://security-tracker.debian.org/tracker/xen

Tenable has extracted the preceding description block directly from the Debian security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote SUSE Linux SLED15 / SLES15 host has packages installed that are affected by multiple vulnerabilities as referenced in the SUSE-SU-2021:3888-1 advisory.

  - PCI devices with RMRRs not deassigned correctly Certain PCI devices in a system might be assigned Reserved     Memory Regions (specified via Reserved Memory Region Reporting, RMRR). These are typically used for     platform tasks such as legacy USB emulation. If such a device is passed through to a guest, then on guest     shutdown the device is not properly deassigned. The IOMMU configuration for these devices which are not     properly deassigned ends up pointing to a freed data structure, including the IO Pagetables. Subsequent     DMA or interrupts from the device will have unpredictable behaviour, ranging from IOMMU faults to memory     corruption. (CVE-2021-28702)

  - 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.
    (Patch 1, combining the fix to both these two issues.) In addition handling of XENMEM_decrease_reservation     can also trigger a host crash when the specified page order is neither 4k nor 2M nor 1G (CVE-2021-28708,     patch 2). (CVE-2021-28704, CVE-2021-28707, CVE-2021-28708)

  - 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. There are two code paths affected - page removal     (CVE-2021-28705) and insertion of new pages (CVE-2021-28709). (We provide one patch which combines the fix     to both issues.) (CVE-2021-28705, CVE-2021-28709)

  - 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. (CVE-2021-28706)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote SUSE Linux SLED12 / SLES12 / SLES_SAP12 host has packages installed that are affected by multiple vulnerabilities as referenced in the SUSE-SU-2021:3852-1 advisory.

  - PCI devices with RMRRs not deassigned correctly Certain PCI devices in a system might be assigned Reserved     Memory Regions (specified via Reserved Memory Region Reporting, RMRR). These are typically used for     platform tasks such as legacy USB emulation. If such a device is passed through to a guest, then on guest     shutdown the device is not properly deassigned. The IOMMU configuration for these devices which are not     properly deassigned ends up pointing to a freed data structure, including the IO Pagetables. Subsequent     DMA or interrupts from the device will have unpredictable behaviour, ranging from IOMMU faults to memory     corruption. (CVE-2021-28702)

  - 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.
    (Patch 1, combining the fix to both these two issues.) In addition handling of XENMEM_decrease_reservation     can also trigger a host crash when the specified page order is neither 4k nor 2M nor 1G (CVE-2021-28708,     patch 2). (CVE-2021-28704, CVE-2021-28707, CVE-2021-28708)

  - 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. There are two code paths affected - page removal     (CVE-2021-28705) and insertion of new pages (CVE-2021-28709). (We provide one patch which combines the fix     to both issues.) (CVE-2021-28705, CVE-2021-28709)

  - 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. (CVE-2021-28706)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote SUSE Linux SLES15 / SLES_SAP15 host has packages installed that are affected by multiple vulnerabilities as referenced in the SUSE-SU-2021:3842-1 advisory.

  - Another race in XENMAPSPACE_grant_table handling Guests are 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, are de-allocated when a guest switches (back) from v2 to v1. Freeing     such pages requires that the hypervisor enforce that no parallel request can result in the addition of a     mapping of such a page to a guest. That enforcement was missing, allowing guests to retain access to pages     that were freed and perhaps re-used for other purposes. Unfortunately, when XSA-379 was being prepared,     this similar issue was not noticed. (CVE-2021-28701)

  - 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.
    (Patch 1, combining the fix to both these two issues.) In addition handling of XENMEM_decrease_reservation     can also trigger a host crash when the specified page order is neither 4k nor 2M nor 1G (CVE-2021-28708,     patch 2). (CVE-2021-28704, CVE-2021-28707, CVE-2021-28708)

  - 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. There are two code paths affected - page removal     (CVE-2021-28705) and insertion of new pages (CVE-2021-28709). (We provide one patch which combines the fix     to both issues.) (CVE-2021-28705, CVE-2021-28709)

  - 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. (CVE-2021-28706)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote SUSE Linux SLES12 / SLES_SAP12 host has packages installed that are affected by multiple vulnerabilities as referenced in the SUSE-SU-2021:3851-1 advisory.

  - 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.
    (Patch 1, combining the fix to both these two issues.) In addition handling of XENMEM_decrease_reservation     can also trigger a host crash when the specified page order is neither 4k nor 2M nor 1G (CVE-2021-28708,     patch 2). (CVE-2021-28704, CVE-2021-28707, CVE-2021-28708)

  - 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. There are two code paths affected - page removal     (CVE-2021-28705) and insertion of new pages (CVE-2021-28709). (We provide one patch which combines the fix     to both issues.) (CVE-2021-28705, CVE-2021-28709)

  - 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. (CVE-2021-28706)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote SUSE Linux SLES12 / SLES_SAP12 host has packages installed that are affected by multiple vulnerabilities as referenced in the SUSE-SU-2021:3849-1 advisory.

  - Another race in XENMAPSPACE_grant_table handling Guests are 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, are de-allocated when a guest switches (back) from v2 to v1. Freeing     such pages requires that the hypervisor enforce that no parallel request can result in the addition of a     mapping of such a page to a guest. That enforcement was missing, allowing guests to retain access to pages     that were freed and perhaps re-used for other purposes. Unfortunately, when XSA-379 was being prepared,     this similar issue was not noticed. (CVE-2021-28701)

  - 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.
    (Patch 1, combining the fix to both these two issues.) In addition handling of XENMEM_decrease_reservation     can also trigger a host crash when the specified page order is neither 4k nor 2M nor 1G (CVE-2021-28708,     patch 2). (CVE-2021-28704, CVE-2021-28707, CVE-2021-28708)

  - 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. There are two code paths affected - page removal     (CVE-2021-28705) and insertion of new pages (CVE-2021-28709). (We provide one patch which combines the fix     to both issues.) (CVE-2021-28705, CVE-2021-28709)

  - 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. (CVE-2021-28706)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote SUSE Linux SLES12 host has packages installed that are affected by multiple vulnerabilities as referenced in the SUSE-SU-2021:3813-1 advisory.

  - 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.
    (Patch 1, combining the fix to both these two issues.) In addition handling of XENMEM_decrease_reservation     can also trigger a host crash when the specified page order is neither 4k nor 2M nor 1G (CVE-2021-28708,     patch 2). (CVE-2021-28704, CVE-2021-28707, CVE-2021-28708)

  - 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. There are two code paths affected - page removal     (CVE-2021-28705) and insertion of new pages (CVE-2021-28709). (We provide one patch which combines the fix     to both issues.) (CVE-2021-28705, CVE-2021-28709)

  - 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. (CVE-2021-28706)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

ID	Name	Product	Family	Severity
258402	Linux Distros Unpatched Vulnerability : CVE-2021-28707	Nessus	Misc.	high
189976	GLSA-202402-07 : Xen: Multiple Vulnerabilities	Nessus	Gentoo Local Security Checks	high
155990	SUSE SLES15 Security Update : xen (SUSE-SU-2021:3977-1)	Nessus	SuSE Local Security Checks	high
155932	openSUSE 15 Security Update : xen (openSUSE-SU-2021:3968-1)	Nessus	SuSE Local Security Checks	high
155929	SUSE SLED15 / SLES15 Security Update : xen (SUSE-SU-2021:3968-1)	Nessus	SuSE Local Security Checks	high
155875	openSUSE 15 Security Update : xen (openSUSE-SU-2021:1543-1)	Nessus	SuSE Local Security Checks	high
155870	Debian DSA-5017-1 : xen - security update	Nessus	Debian Local Security Checks	high
155856	SUSE SLED15 / SLES15 Security Update : xen (SUSE-SU-2021:3888-1)	Nessus	SuSE Local Security Checks	high
155808	SUSE SLED12 / SLES12 Security Update : xen (SUSE-SU-2021:3852-1)	Nessus	SuSE Local Security Checks	high
155804	SUSE SLES15 Security Update : xen (SUSE-SU-2021:3842-1)	Nessus	SuSE Local Security Checks	high
155803	SUSE SLES12 Security Update : xen (SUSE-SU-2021:3851-1)	Nessus	SuSE Local Security Checks	high
155793	SUSE SLES12 Security Update : xen (SUSE-SU-2021:3849-1)	Nessus	SuSE Local Security Checks	high
155723	SUSE SLES12 Security Update : xen (SUSE-SU-2021:3813-1)	Nessus	SuSE Local Security Checks	high

Detections

Analytics

CVE-2021-28707

high

Tenable Plugins

high

high

high

high

high

high

high

high

high

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high