{"id":"CVE-2021-3656","details":"A flaw was found in the KVM's AMD code for supporting SVM nested virtualization. The flaw occurs when processing the VMCB (virtual machine control block) provided by the L1 guest to spawn/handle a nested guest (L2). Due to improper validation of the \"virt_ext\" field, this issue could allow a malicious L1 to disable both VMLOAD/VMSAVE intercepts and VLS (Virtual VMLOAD/VMSAVE) for the L2 guest. As a result, the L2 guest would be allowed to read/write physical pages of the host, resulting in a crash of the entire system, leak of sensitive data or potential guest-to-host escape.","modified":"2026-10-06T02:24:35.602014683Z","published":"2022-03-04T19:15:08.677Z","related":["ALSA-2021:4056","SUSE-SU-2021:3073-1","SUSE-SU-2021:3177-1","SUSE-SU-2021:3178-1","SUSE-SU-2021:3179-1","SUSE-SU-2021:3192-1","SUSE-SU-2021:3205-1","SUSE-SU-2021:3205-2","SUSE-SU-2021:3206-1","SUSE-SU-2021:3207-1","SUSE-SU-2021:3217-1","SUSE-SU-2021:3415-1","SUSE-SU-2021:3876-1","SUSE-SU-2021:3969-1","SUSE-SU-2021:3972-1","openSUSE-SU-2021:1271-1","openSUSE-SU-2021:3179-1","openSUSE-SU-2021:3205-1","openSUSE-SU-2021:3876-1","openSUSE-SU-2024:10728-1","openSUSE-SU-2024:13704-1"],"database_specific":{"unresolved_ranges":[{"cpe":"cpe:2.3:a:redhat:3scale_api_management:2.0:*:*:*:*:*:*:*","extracted_events":[{"last_affected":"2.0"}],"source":"CPE_FIELD"},{"source":"CPE_FIELD","cpe":"cpe:2.3:a:redhat:openstack:13:*:*:*:*:*:*:*","extracted_events":[{"last_affected":"13"}]},{"source":"CPE_FIELD","cpe":"cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*","extracted_events":[{"last_affected":"33"}]},{"cpe":"cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*","extracted_events":[{"last_affected":"34"}],"source":"CPE_FIELD"},{"source":"CPE_FIELD","cpe":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","extracted_events":[{"introduced":"4.13"},{"fixed":"4.14.245"},{"introduced":"4.15"},{"fixed":"4.19.205"},{"introduced":"4.20"},{"fixed":"5.4.142"},{"introduced":"5.5"},{"fixed":"5.10.60"},{"introduced":"5.11"},{"fixed":"5.13.12"}]},{"cpe":"cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*","extracted_events":[{"last_affected":"8.0"}],"source":"CPE_FIELD"},{"cpe":"cpe:2.3:o:redhat:enterprise_linux_eus:8.1:*:*:*:*:*:*:*","extracted_events":[{"last_affected":"8.1"}],"source":"CPE_FIELD"},{"source":"CPE_FIELD","cpe":"cpe:2.3:o:redhat:enterprise_linux_eus:8.2:*:*:*:*:*:*:*","extracted_events":[{"last_affected":"8.2"}]},{"cpe":"cpe:2.3:o:redhat:enterprise_linux_eus:8.4:*:*:*:*:*:*:*","extracted_events":[{"last_affected":"8.4"}],"source":"CPE_FIELD"},{"cpe":"cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems:8.0:*:*:*:*:*:*:*","extracted_events":[{"last_affected":"8.0"}],"source":"CPE_FIELD"},{"source":"CPE_FIELD","cpe":"cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems_eus:8.1:*:*:*:*:*:*:*","extracted_events":[{"last_affected":"8.1"}]},{"cpe":"cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems_eus:8.2:*:*:*:*:*:*:*","extracted_events":[{"last_affected":"8.2"}],"source":"CPE_FIELD"},{"extracted_events":[{"last_affected":"8.4"}],"source":"CPE_FIELD","cpe":"cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems_eus:8.4:*:*:*:*:*:*:*"},{"cpe":"cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian:8.0:*:*:*:*:*:*:*","extracted_events":[{"last_affected":"8.0"}],"source":"CPE_FIELD"},{"source":"CPE_FIELD","cpe":"cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_eus:8.1:*:*:*:*:*:*:*","extracted_events":[{"last_affected":"8.1"}]},{"source":"CPE_FIELD","cpe":"cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_eus:8.2:*:*:*:*:*:*:*","extracted_events":[{"last_affected":"8.2"}]},{"extracted_events":[{"last_affected":"8.4"}],"source":"CPE_FIELD","cpe":"cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_eus:8.4:*:*:*:*:*:*:*"},{"source":"CPE_FIELD","cpe":"cpe:2.3:o:redhat:enterprise_linux_for_real_time:8:*:*:*:*:*:*:*","extracted_events":[{"last_affected":"8"}]},{"cpe":"cpe:2.3:o:redhat:enterprise_linux_for_real_time_for_nfv:8:*:*:*:*:*:*:*","extracted_events":[{"last_affected":"8"}],"source":"CPE_FIELD"},{"extracted_events":[{"last_affected":"8.2"}],"source":"CPE_FIELD","cpe":"cpe:2.3:o:redhat:enterprise_linux_for_real_time_for_nfv_tus:8.2:*:*:*:*:*:*:*"},{"cpe":"cpe:2.3:o:redhat:enterprise_linux_for_real_time_for_nfv_tus:8.4:*:*:*:*:*:*:*","extracted_events":[{"last_affected":"8.4"}],"source":"CPE_FIELD"},{"cpe":"cpe:2.3:o:redhat:enterprise_linux_for_real_time_tus:8.2:*:*:*:*:*:*:*","extracted_events":[{"last_affected":"8.2"}],"source":"CPE_FIELD"},{"extracted_events":[{"last_affected":"8.4"}],"source":"CPE_FIELD","cpe":"cpe:2.3:o:redhat:enterprise_linux_for_real_time_tus:8.4:*:*:*:*:*:*:*"},{"source":"CPE_FIELD","cpe":"cpe:2.3:o:redhat:enterprise_linux_server_aus:7.6:*:*:*:*:*:*:*","extracted_events":[{"last_affected":"7.6"}]},{"cpe":"cpe:2.3:o:redhat:enterprise_linux_server_aus:7.7:*:*:*:*:*:*:*","extracted_events":[{"last_affected":"7.7"}],"source":"CPE_FIELD"},{"cpe":"cpe:2.3:o:redhat:enterprise_linux_server_aus:8.2:*:*:*:*:*:*:*","extracted_events":[{"last_affected":"8.2"}],"source":"CPE_FIELD"},{"extracted_events":[{"last_affected":"8.4"}],"source":"CPE_FIELD","cpe":"cpe:2.3:o:redhat:enterprise_linux_server_aus:8.4:*:*:*:*:*:*:*"},{"cpe":"cpe:2.3:o:redhat:enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions:7.6:*:*:*:*:*:*:*","extracted_events":[{"last_affected":"7.6"}],"source":"CPE_FIELD"},{"cpe":"cpe:2.3:o:redhat:enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions:8.1:*:*:*:*:*:*:*","extracted_events":[{"last_affected":"8.1"}],"source":"CPE_FIELD"}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