CVE-2021-3656Not scoredCWE-862

CVE-2021-3656: Linux KVM vulnerability

Linux · KVM

Affected: Linux KVM · Exploitation: unlikely (under 1%)

Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.

0.7%probability of exploitation in the next 30 days

52nd percentile

050100

Higher than 52% of scored CVEs

Not scored yet. The CVE record carries no CVSS score.

DescriptionCVE.org

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.

Affected products1

From the CVE record. A product or version that is not listed is unknown, not unaffected.

KVMFixed-In v5.14-rc7 and above

On the Atlas

Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.

Open the Atlas

Exploitation: Unlikely (under 1%). EPSS under 1%, or no score yet.
CISA KEV: Not listed
Public check: No public nuclei template
Weakness: Missing Authorization · Access Control
Vendor: Linux
Published: March 2022
Band: Unlikely (under 1%), March 2022

CoverageNo articles yet

No CyberSIXT article names CVE-2021-3656 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.