// For flags

CVE-2019-7221

Kernel: KVM: nVMX: use-after-free of the hrtimer for emulation of the preemption timer

Severity Score

7.8
*CVSS v3

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

1
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

The KVM implementation in the Linux kernel through 4.20.5 has a Use-after-Free.

La implementaciĆ³n KVM en el kernel de Linux, hasta la versiĆ³n 4.20.5, tiene un uso de memoria previamente liberada.

A use-after-free vulnerability was found in the way the Linux kernel's KVM hypervisor emulates a preemption timer for L2 guests when nested (=1) virtualization is enabled. This high resolution timer(hrtimer) runs when a L2 guest is active. After VM exit, the sync_vmcs12() timer object is stopped. The use-after-free occurs if the timer object is freed before calling sync_vmcs12() routine. A guest user/process could use this flaw to crash the host kernel resulting in a denial of service or, potentially, gain privileged access to a system.

KVM suffers from a use-after-free vulnerability after using the emulated VMX preemption timer.

*Credits: N/A
CVSS Scores
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Attack Vector
Local
Attack Complexity
High
Privileges Required
High
User Interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High
Attack Vector
Local
Attack Complexity
Low
Authentication
None
Confidentiality
Partial
Integrity
Partial
Availability
Partial
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2019-01-30 CVE Reserved
  • 2019-02-16 CVE Published
  • 2024-03-10 EPSS Updated
  • 2024-08-04 CVE Updated
  • 2024-08-04 First Exploit
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
CWE
  • CWE-416: Use After Free
CAPEC
References (26)
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Linux
Search vendor "Linux"
Linux Kernel
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<= 4.20.5
Search vendor "Linux" for product "Linux Kernel" and version " <= 4.20.5"
-
Affected
Opensuse
Search vendor "Opensuse"
Leap
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15.0
Search vendor "Opensuse" for product "Leap" and version "15.0"
-
Affected
Fedoraproject
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Fedora
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28
Search vendor "Fedoraproject" for product "Fedora" and version "28"
-
Affected
Fedoraproject
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Fedora
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29
Search vendor "Fedoraproject" for product "Fedora" and version "29"
-
Affected
Debian
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Debian Linux
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8.0
Search vendor "Debian" for product "Debian Linux" and version "8.0"
-
Affected
Canonical
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Ubuntu Linux
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14.04
Search vendor "Canonical" for product "Ubuntu Linux" and version "14.04"
lts
Affected
Canonical
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Ubuntu Linux
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16.04
Search vendor "Canonical" for product "Ubuntu Linux" and version "16.04"
lts
Affected
Canonical
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Ubuntu Linux
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18.04
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lts
Affected
Canonical
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Ubuntu Linux
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18.10
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-
Affected
Netapp
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Active Iq Performance Analytics Services
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--
Affected
Netapp
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Element Software Management Node
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--
Affected
Redhat
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Openshift Container Platform
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3.11
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-
Affected
Redhat
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Enterprise Linux
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7.0
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-
Affected
Redhat
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Enterprise Linux Desktop
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7.0
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-
Affected
Redhat
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Enterprise Linux Server
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7.0
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-
Affected
Redhat
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Enterprise Linux Server Aus
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7.6
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-
Affected
Redhat
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Enterprise Linux Server Eus
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7.6
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-
Affected
Redhat
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Enterprise Linux Server Tus
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7.6
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-
Affected
Redhat
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Enterprise Linux Workstation
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7.0
Search vendor "Redhat" for product "Enterprise Linux Workstation" and version "7.0"
-
Affected