Executive Summary

Informations
Name CVE-2021-29657 First vendor Publication 2021-07-22
Vendor Cve Last vendor Modification 2021-10-18

Security-Database Scoring CVSS v3

Cvss vector : CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Overall CVSS Score 7.4
Base Score 7.4 Environmental Score 7.4
impact SubScore 5.9 Temporal Score 7.4
Exploitabality Sub Score 1.4
 
Attack Vector Local Attack Complexity High
Privileges Required None User Interaction None
Scope Unchanged Confidentiality Impact High
Integrity Impact High Availability Impact High
Calculate full CVSS 3.0 Vectors scores

Security-Database Scoring CVSS v2

Cvss vector : (AV:L/AC:M/Au:N/C:C/I:C/A:C)
Cvss Base Score 6.9 Attack Range Local
Cvss Impact Score 10 Attack Complexity Medium
Cvss Expoit Score 3.4 Authentication None Required
Calculate full CVSS 2.0 Vectors scores

Detail

arch/x86/kvm/svm/nested.c in the Linux kernel before 5.11.12 has a use-after-free in which an AMD KVM guest can bypass access control on host OS MSRs when there are nested guests, aka CID-a58d9166a756. This occurs because of a TOCTOU race condition associated with a VMCB12 double fetch in nested_svm_vmrun.

Original Source

Url : http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-29657

CWE : Common Weakness Enumeration

% Id Name
50 % CWE-416 Use After Free
50 % CWE-367 Time-of-check Time-of-use (TOCTOU) Race Condition

CPE : Common Platform Enumeration

TypeDescriptionCount
Os 3390

Sources (Detail)

Source Url
CONFIRM https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.11.12
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id...
https://security.netapp.com/advisory/ntap-20210902-0008/
MISC http://packetstormsecurity.com/files/163324/KVM-nested_svm_vmrun-Double-Fetch...
https://bugs.chromium.org/p/project-zero/issues/detail?id=2177

Alert History

If you want to see full details history, please login or register.
0
1
2
3
4
5
6
7
8
Date Informations
2021-10-18 17:23:05
  • Multiple Updates
2021-09-10 00:23:02
  • Multiple Updates
2021-09-09 21:22:53
  • Multiple Updates
2021-09-02 13:23:00
  • Multiple Updates
2021-08-26 12:42:59
  • Multiple Updates
2021-08-24 01:43:30
  • Multiple Updates
2021-08-19 09:22:59
  • Multiple Updates
2021-08-11 21:23:19
  • Multiple Updates
2021-07-22 21:23:08
  • First insertion