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CVE Record

CVE-2020-2732: A flaw was discovered in the way that the KVM hypervisor handled instruction emulation for an L2 guest when...

A flaw was discovered in the way that the KVM hypervisor handled instruction emulation for an L2 guest when nested virtualisation is enabled. Under some circumstances, an L2 guest may trick the L0 guest into accessing sensitive L1 resources that should be inaccessible to the L2 guest.

MediumCVSS 5.8Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2020-2732 is a KVM nested virtualization flaw. A lower-level guest could cause the host hypervisor to access resources belonging to the intermediate guest that should remain isolated. The main business concern is confidentiality exposure on virtualization hosts that allow nested guests.

Executive priority

Treat as a targeted virtualization confidentiality risk. Patch during normal maintenance, but accelerate for shared KVM platforms, cloud-like environments, or systems where less-trusted tenants can run nested guests.

Technical view

The issue is in KVM instruction emulation when nested virtualization is enabled. An L2 guest, under some circumstances, may induce access to sensitive L1 resources. CVSS 3.1 is 5.8 with adjacent attack vector, high attack complexity, low privileges, changed scope, and high confidentiality impact.

Likely exposure

Exposure is most likely on KVM hosts running affected Oracle Linux 6 or 7 kernels with nested virtualization enabled. The bundle also cites Debian kernel advisories, but the provided affected-product list names Oracle Linux only.

Exploitation context

The source bundle does not show CISA KEV listing or cited evidence of active exploitation. Exploitation appears constrained by nested virtualization, adjacent access, low privileges, and high complexity, but confidentiality impact can be serious on shared virtualization infrastructure.

Researcher notes

Evidence is strongest for a KVM nested virtualization isolation flaw and upstream Linux kernel fixes. The bundle does not include exploit details, public exploit confirmation, or KEV status. Avoid broad product claims beyond cited advisories and the supplied affected list.

Mitigation direction

  • Apply relevant Oracle Linux kernel errata for affected 6 or 7 systems.
  • Review Debian advisories if Debian kernel packages are in scope.
  • Check vendor guidance for exact fixed kernel package versions.
  • Disable nested virtualization for untrusted workloads if patching is delayed.
  • Prioritize shared or multi-tenant virtualization hosts before isolated lab systems.

Validation and detection

  • Inventory KVM hosts and identify systems with nested virtualization enabled.
  • Confirm whether Oracle Linux 6 or 7 affected kernels are deployed.
  • Compare installed kernel packages against vendor errata and advisories.
  • Review whether untrusted users can create or control nested guests.
  • Verify patched hosts have rebooted into the fixed kernel.
Prepared
Confidence
medium
Sources
11

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

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CVE-2020-2732 mapping review

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Vulnerability profileCVE Program record
Severity
Medium
CVSS
5.8 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

1CVSS vectors
0Timeline events
0ADP providers
15Source links

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
5.8CVSS 3.1MediumCVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N1.34Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

5.8Medium
CVSS 3.1 vector shape for CVE-2020-2732Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
Oracle CorporationOracle Linux7, 6Listed
Weakness

CWE details

No CWE listed

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