CVE-2021-3656

CVSS V2 High 7.2 CVSS V3 High 8.8
Description
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.
Overview
  • CVE ID
  • CVE-2021-3656
  • Assigner
  • secalert@redhat.com
  • Vulnerability Status
  • Analyzed
  • Published Version
  • 2022-03-04T19:15:08
  • Last Modified Date
  • 2023-01-19T15:53:14
Weakness Enumerations
CWE URL
CWE-862 http://cwe.mitre.org/data/definitions/862.html
CPE Configuration (Product)
CPE Vulnerable Operator Version Start Version End
AND
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* 1 OR 4.13 5.14
cpe:2.3:o:linux:linux_kernel:5.14:-:*:*:*:*:*:* 1 OR
cpe:2.3:o:linux:linux_kernel:5.14:rc1:*:*:*:*:*:* 1 OR
cpe:2.3:o:linux:linux_kernel:5.14:rc2:*:*:*:*:*:* 1 OR
cpe:2.3:o:linux:linux_kernel:5.14:rc3:*:*:*:*:*:* 1 OR
cpe:2.3:o:linux:linux_kernel:5.14:rc4:*:*:*:*:*:* 1 OR
cpe:2.3:o:linux:linux_kernel:5.14:rc5:*:*:*:*:*:* 1 OR
cpe:2.3:o:linux:linux_kernel:5.14:rc6:*:*:*:*:*:* 1 OR
AND
cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:* 1 OR
AND
cpe:2.3:a:redhat:software_collections:-:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux_server:7.0:*:*:*:*:*:*:* 0 OR
AND
cpe:2.3:a:redhat:openstack:13:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux_desktop:7.0:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux_eus:8.1:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux_eus:8.2:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux_eus:8.4:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems:7.0:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems:8.0:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems_eus:8.1:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems_eus:8.2:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems_eus:8.4:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux_for_power_big_endian:7.0:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian:7.0:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian:8.0:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_eus:8.1:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_eus:8.2:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_eus:8.4:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux_for_real_time:7:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux_for_real_time:8:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux_for_real_time_for_nfv:7:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux_for_real_time_for_nfv:8:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux_for_real_time_for_nfv_tus:8.2:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux_for_real_time_for_nfv_tus:8.4:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux_for_real_time_tus:8.2:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux_for_real_time_tus:8.4:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux_for_scientific_computing:7.0:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux_server:7.0:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux_server_aus:7.6:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux_server_aus:7.7:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux_server_aus:8.2:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux_server_aus:8.4:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions:7.6:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions:8.1:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions:8.2:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions:8.4:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux_server_tus:7.6:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux_server_tus:7.7:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux_server_tus:8.2:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux_server_tus:8.4:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux_server_update_services_for_sap_solutions:7.6:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux_server_update_services_for_sap_solutions:7.7:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux_server_update_services_for_sap_solutions:8.1:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux_server_update_services_for_sap_solutions:8.2:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux_server_update_services_for_sap_solutions:8.4:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux_workstation:7.0:*:*:*:*:*:*:* 1 OR
AND
cpe:2.3:a:redhat:3scale_api_management:2.0:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:* 0 OR
cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* 0 OR
AND
cpe:2.3:a:redhat:codeready_linux_builder:-:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* 0 OR
cpe:2.3:o:redhat:enterprise_linux_eus:8.1:*:*:*:*:*:*:* 0 OR
cpe:2.3:o:redhat:enterprise_linux_eus:8.2:*:*:*:*:*:*:* 0 OR
cpe:2.3:o:redhat:enterprise_linux_eus:8.4:*:*:*:*:*:*:* 0 OR
cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian:8.0:*:*:*:*:*:*:* 0 OR
cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_eus:8.1:*:*:*:*:*:*:* 0 OR
cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_eus:8.2:*:*:*:*:*:*:* 0 OR
cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_eus:8.4:*:*:*:*:*:*:* 0 OR
AND
cpe:2.3:a:redhat:virtualization_host:4.0:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:* 0 OR
cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* 0 OR
CVSS Version 2
  • Version
  • 2.0
  • Vector String
  • AV:L/AC:L/Au:N/C:C/I:C/A:C
  • Access Vector
  • LOCAL
  • Access Compatibility
  • LOW
  • Authentication
  • NONE
  • Confidentiality Impact
  • COMPLETE
  • Integrity Impact
  • COMPLETE
  • Availability Impact
  • COMPLETE
  • Base Score
  • 7.2
  • Severity
  • HIGH
  • Exploitability Score
  • 3.9
  • Impact Score
  • 10
CVSS Version 3
  • Version
  • 3.1
  • Vector String
  • CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
  • Attack Vector
  • LOCAL
  • Attack Compatibility
  • LOW
  • Privileges Required
  • LOW
  • User Interaction
  • NONE
  • Scope
  • CHANGED
  • Confidentiality Impact
  • HIGH
  • Availability Impact
  • HIGH
  • Base Score
  • 8.8
  • Base Severity
  • HIGH
  • Exploitability Score
  • 2
  • Impact Score
  • 6
References
Reference URL Reference Tags
https://www.openwall.com/lists/oss-security/2021/08/16/1 Mailing List Third Party Advisory
https://github.com/torvalds/linux/commit/c7dfa4009965a9b2d7b329ee970eb8da0d32f0bc Patch Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=1983988 Issue Tracking Third Party Advisory
https://git.kernel.org/pub/scm/virt/kvm/kvm.git/commit/?id=c7dfa4009965a9b2d7b329ee970eb8da0d32f0bc Patch Third Party Advisory
Sources
Source Name Source URL
NIST https://nvd.nist.gov/vuln/detail/CVE-2021-3656
MITRE https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-3656
History
Created Old Value New Value Data Type Notes
2022-05-10 15:46:20 Added to TrackCVE
2022-12-06 11:21:47 2022-03-04T19:15Z 2022-03-04T19:15:08 CVE Published Date updated
2022-12-06 11:21:47 2022-03-10T18:55:35 CVE Modified Date updated
2022-12-06 11:21:47 Undergoing Analysis Vulnerability Status updated
2023-01-19 16:13:31 2023-01-19T15:53:14 CVE Modified Date updated
2023-01-19 16:13:31 Undergoing Analysis Analyzed Vulnerability Status updated