Attacker Value
Unknown
(0 users assessed)
Exploitability
Unknown
(0 users assessed)
User Interaction
None
Privileges Required
Low
Attack Vector
Local
0

CVE-2021-3656

Disclosure Date: March 04, 2022
Add MITRE ATT&CK tactics and techniques that apply to this CVE.

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.

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CVSS V3 Severity and Metrics
Base Score:
8.8 High
Impact Score:
6
Exploitability Score:
2
Vector:
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Attack Vector (AV):
Local
Attack Complexity (AC):
Low
Privileges Required (PR):
Low
User Interaction (UI):
None
Scope (S):
Changed
Confidentiality (C):
High
Integrity (I):
High
Availability (A):
High

General Information

Vendors

  • fedoraproject,
  • linux,
  • redhat

Products

  • 3scale api management 2.0,
  • codeready linux builder -,
  • enterprise linux 8.0,
  • enterprise linux desktop 7.0,
  • enterprise linux eus 8.1,
  • enterprise linux eus 8.2,
  • enterprise linux eus 8.4,
  • enterprise linux for ibm z systems 7.0,
  • enterprise linux for ibm z systems 8.0,
  • enterprise linux for ibm z systems eus 8.1,
  • enterprise linux for ibm z systems eus 8.2,
  • enterprise linux for ibm z systems eus 8.4,
  • enterprise linux for power big endian 7.0,
  • enterprise linux for power little endian 7.0,
  • enterprise linux for power little endian 8.0,
  • enterprise linux for power little endian eus 8.1,
  • enterprise linux for power little endian eus 8.2,
  • enterprise linux for power little endian eus 8.4,
  • enterprise linux for real time 7,
  • enterprise linux for real time 8,
  • enterprise linux for real time for nfv 7,
  • enterprise linux for real time for nfv 8,
  • enterprise linux for real time for nfv tus 8.2,
  • enterprise linux for real time for nfv tus 8.4,
  • enterprise linux for real time tus 8.2,
  • enterprise linux for real time tus 8.4,
  • enterprise linux for scientific computing 7.0,
  • enterprise linux server 7.0,
  • enterprise linux server aus 7.6,
  • enterprise linux server aus 7.7,
  • enterprise linux server aus 8.2,
  • enterprise linux server aus 8.4,
  • enterprise linux server for power little endian update services for sap solutions 7.6,
  • enterprise linux server for power little endian update services for sap solutions 8.1,
  • enterprise linux server for power little endian update services for sap solutions 8.2,
  • enterprise linux server for power little endian update services for sap solutions 8.4,
  • enterprise linux server tus 7.6,
  • enterprise linux server tus 7.7,
  • enterprise linux server tus 8.2,
  • enterprise linux server tus 8.4,
  • enterprise linux server update services for sap solutions 7.6,
  • enterprise linux server update services for sap solutions 7.7,
  • enterprise linux server update services for sap solutions 8.1,
  • enterprise linux server update services for sap solutions 8.2,
  • enterprise linux server update services for sap solutions 8.4,
  • enterprise linux workstation 7.0,
  • fedora 33,
  • fedora 34,
  • linux kernel,
  • linux kernel 5.14,
  • openstack 13,
  • software collections -,
  • virtualization host 4.0
Technical Analysis