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.
Published: 2022-03-04
Score: 8.8 High
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
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Remediation

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Advisories
Source ID Title
Debian DLA Debian DLA DLA-2785-1 linux-4.19 security update
Debian DSA Debian DSA DSA-4978-1 linux security update
EUVD EUVD EUVD-2021-26951 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.
Ubuntu USN Ubuntu USN USN-5070-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-5071-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-5071-2 Linux kernel (HWE) vulnerabilities
Ubuntu USN Ubuntu USN USN-5072-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-5073-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-5073-2 Linux kernel (GCP) vulnerabilities
Ubuntu USN Ubuntu USN USN-5082-1 Linux kernel (OEM) vulnerabilities
History

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Subscriptions

Fedoraproject Fedora
Linux Linux Kernel
Redhat 3scale Api Management Codeready Linux Builder Enterprise Linux Enterprise Linux Desktop Enterprise Linux Eus Enterprise Linux For Ibm Z Systems Enterprise Linux For Ibm Z Systems Eus Enterprise Linux For Power Big Endian Enterprise Linux For Power Little Endian Enterprise Linux For Power Little Endian Eus Enterprise Linux For Real Time Enterprise Linux For Real Time For Nfv Enterprise Linux For Real Time For Nfv Tus Enterprise Linux For Real Time Tus Enterprise Linux For Scientific Computing Enterprise Linux Server Enterprise Linux Server Aus Enterprise Linux Server For Power Little Endian Update Services For Sap Solutions Enterprise Linux Server Tus Enterprise Linux Server Update Services For Sap Solutions Enterprise Linux Workstation Openstack Rhel Aus Rhel E4s Rhel Eus Rhel Extras Rt Rhel Tus Software Collections Virtualization Host
cve-icon MITRE

Status: PUBLISHED

Assigner: redhat

Published:

Updated: 2024-08-03T17:01:07.792Z

Reserved: 2021-07-21T00:00:00.000Z

Link: CVE-2021-3656

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Modified

Published: 2022-03-04T19:15:08.677

Modified: 2024-11-21T06:22:05.187

Link: CVE-2021-3656

cve-icon Redhat

Severity : Moderate

Publid Date: 2021-08-16T12:00:00Z

Links: CVE-2021-3656 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses