Executive Summary

Informations
Name CVE-2020-8834 First vendor Publication 2020-04-09
Vendor Cve Last vendor Modification 2022-10-07

Security-Database Scoring CVSS v3

Cvss vector : CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
Overall CVSS Score 6.5
Base Score 6.5 Environmental Score 6.5
impact SubScore 4 Temporal Score 6.5
Exploitabality Sub Score 2
 
Attack Vector Local Attack Complexity Low
Privileges Required Low User Interaction None
Scope Changed Confidentiality Impact None
Integrity Impact None Availability Impact High
Calculate full CVSS 3.0 Vectors scores

Security-Database Scoring CVSS v2

Cvss vector : (AV:L/AC:L/Au:N/C:N/I:N/A:C)
Cvss Base Score 4.9 Attack Range Local
Cvss Impact Score 6.9 Attack Complexity Low
Cvss Expoit Score 3.9 Authentication None Required
Calculate full CVSS 2.0 Vectors scores

Detail

KVM in the Linux kernel on Power8 processors has a conflicting use of HSTATE_HOST_R1 to store r1 state in kvmppc_hv_entry plus in kvmppc_{save,restore}_tm, leading to a stack corruption. Because of this, an attacker with the ability run code in kernel space of a guest VM can cause the host kernel to panic. There were two commits that, according to the reporter, introduced the vulnerability: f024ee098476 ("KVM: PPC: Book3S HV: Pull out TM state save/restore into separate procedures") 87a11bb6a7f7 ("KVM: PPC: Book3S HV: Work around XER[SO] bug in fake suspend mode") The former landed in 4.8, the latter in 4.17. This was fixed without realizing the impact in 4.18 with the following three commits, though it's believed the first is the only strictly necessary commit: 6f597c6b63b6 ("KVM: PPC: Book3S PR: Add guest MSR parameter for kvmppc_save_tm()/kvmppc_restore_tm()") 7b0e827c6970 ("KVM: PPC: Book3S HV: Factor fake-suspend handling out of kvmppc_save/restore_tm") 009c872a8bc4 ("KVM: PPC: Book3S PR: Move kvmppc_save_tm/kvmppc_restore_tm to separate file")

Original Source

Url : http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-8834

CWE : Common Weakness Enumeration

% Id Name
100 % CWE-362 Race Condition

CPE : Common Platform Enumeration

TypeDescriptionCount
Os 1

Sources (Detail)

Source Url
CONFIRM https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1867717
https://www.openwall.com/lists/oss-security/2020/04/06/2
SUSE http://lists.opensuse.org/opensuse-security-announce/2020-04/msg00035.html
UBUNTU https://usn.ubuntu.com/4318-1/
https://usn.ubuntu.com/usn/usn-4318-1

Alert History

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0
1
Date Informations
2022-10-07 21:27:52
  • Multiple Updates
2020-05-23 02:40:57
  • First insertion