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

CVE-2020-25602

Disclosure Date: September 23, 2020
Add MITRE ATT&CK tactics and techniques that apply to this CVE.

Description

An issue was discovered in Xen through 4.14.x. An x86 PV guest can trigger a host OS crash when handling guest access to MSR_MISC_ENABLE. When a guest accesses certain Model Specific Registers, Xen first reads the value from hardware to use as the basis for auditing the guest access. For the MISC_ENABLE MSR, which is an Intel specific MSR, this MSR read is performed without error handling for a #GP fault, which is the consequence of trying to read this MSR on non-Intel hardware. A buggy or malicious PV guest administrator can crash Xen, resulting in a host Denial of Service. Only x86 systems are vulnerable. ARM systems are not vulnerable. Only Xen versions 4.11 and onwards are vulnerable. 4.10 and earlier are not vulnerable. Only x86 systems that do not implement the MISC_ENABLE MSR (0x1a0) are vulnerable. AMD and Hygon systems do not implement this MSR and are vulnerable. Intel systems do implement this MSR and are not vulnerable. Other manufacturers have not been checked. Only x86 PV guests can exploit the vulnerability. x86 HVM/PVH guests cannot exploit the vulnerability.

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CVSS V3 Severity and Metrics
Base Score:
6.0 Medium
Impact Score:
4
Exploitability Score:
1.5
Vector:
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:H
Attack Vector (AV):
Local
Attack Complexity (AC):
Low
Privileges Required (PR):
High
User Interaction (UI):
None
Scope (S):
Changed
Confidentiality (C):
None
Integrity (I):
None
Availability (A):
High

General Information

Vendors

  • debian,
  • fedoraproject,
  • opensuse,
  • xen

Products

  • debian linux 10.0,
  • fedora 31,
  • fedora 32,
  • fedora 33,
  • leap 15.2,
  • xen
Technical Analysis