CVEdetails.com the ultimate security vulnerability data source
(e.g.: CVE-2009-1234 or 2010-1234 or 20101234)
Log In   Register
  Take a third party risk management course for FREE
Vulnerability Feeds & WidgetsNew   www.itsecdb.com  

Vulnerability Details : CVE-2021-3656

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.
Publish Date : 2022-03-04 Last Update Date : 2023-01-19
Collapse All   Expand All   Select   Select&Copy  
Search Twitter   Search YouTube   Search Google

- CVSS Scores & Vulnerability Types

CVSS Score
7.2
Confidentiality Impact Complete (There is total information disclosure, resulting in all system files being revealed.)
Integrity Impact Complete (There is a total compromise of system integrity. There is a complete loss of system protection, resulting in the entire system being compromised.)
Availability Impact Complete (There is a total shutdown of the affected resource. The attacker can render the resource completely unavailable.)
Access Complexity Low (Specialized access conditions or extenuating circumstances do not exist. Very little knowledge or skill is required to exploit. )
Authentication Not required (Authentication is not required to exploit the vulnerability.)
Gained Access None
Vulnerability Type(s)
CWE ID 862

- Related OVAL Definitions

Title Definition Id Class Family
RHSA-2021:3801: kernel security and bug fix update (Important) oval:com.redhat.rhsa:def:20213801 unix
RHSA-2021:3802: kernel-rt security and bug fix update (Important) oval:com.redhat.rhsa:def:20213802 unix
RHSA-2021:4056: kernel security, bug fix, and enhancement update (Important) oval:com.redhat.rhsa:def:20214056 unix
RHSA-2021:4088: kernel-rt security and bug fix update (Important) oval:com.redhat.rhsa:def:20214088 unix
OVAL (Open Vulnerability and Assessment Language) definitions define exactly what should be done to verify a vulnerability or a missing patch. Check out the OVAL definitions if you want to learn what you should do to verify a vulnerability.

- Products Affected By CVE-2021-3656

# Product Type Vendor Product Version Update Edition Language
1 OS Fedoraproject Fedora 33 * * * Version Details Vulnerabilities
2 OS Fedoraproject Fedora 34 * * * Version Details Vulnerabilities
3 OS Linux Linux Kernel * * * * Version Details Vulnerabilities
4 OS Linux Linux Kernel 5.14 RC5 * * Version Details Vulnerabilities
5 OS Linux Linux Kernel 5.14 RC1 * * Version Details Vulnerabilities
6 OS Linux Linux Kernel 5.14 RC6 * * Version Details Vulnerabilities
7 OS Linux Linux Kernel 5.14 RC2 * * Version Details Vulnerabilities
8 OS Linux Linux Kernel 5.14 - * * Version Details Vulnerabilities
9 OS Linux Linux Kernel 5.14 RC3 * * Version Details Vulnerabilities
10 OS Linux Linux Kernel 5.14 RC4 * * Version Details Vulnerabilities
11 OS Redhat Enterprise Linux 8.0 * * * Version Details Vulnerabilities
12 OS Redhat Enterprise Linux Desktop 7.0 * * * Version Details Vulnerabilities
13 OS Redhat Enterprise Linux Eus 8.1 * * * Version Details Vulnerabilities
14 OS Redhat Enterprise Linux Eus 8.2 * * * Version Details Vulnerabilities
15 OS Redhat Enterprise Linux Eus 8.4 * * * Version Details Vulnerabilities
16 OS Redhat Enterprise Linux For Ibm Z Systems 7.0 * * * Version Details Vulnerabilities
17 OS Redhat Enterprise Linux For Ibm Z Systems 8.0 * * * Version Details Vulnerabilities
18 OS Redhat Enterprise Linux For Ibm Z Systems Eus 8.1 * * * Version Details Vulnerabilities
19 OS Redhat Enterprise Linux For Ibm Z Systems Eus 8.2 * * * Version Details Vulnerabilities
20 OS Redhat Enterprise Linux For Ibm Z Systems Eus 8.4 * * * Version Details Vulnerabilities
21 OS Redhat Enterprise Linux For Power Big Endian 7.0 * * * Version Details Vulnerabilities
22 OS Redhat Enterprise Linux For Power Little Endian 7.0 * * * Version Details Vulnerabilities
23 OS Redhat Enterprise Linux For Power Little Endian 8.0 * * * Version Details Vulnerabilities
24 OS Redhat Enterprise Linux For Power Little Endian Eus 8.1 * * * Version Details Vulnerabilities
25 OS Redhat Enterprise Linux For Power Little Endian Eus 8.2 * * * Version Details Vulnerabilities
26 OS Redhat Enterprise Linux For Power Little Endian Eus 8.4 * * * Version Details Vulnerabilities
27 OS Redhat Enterprise Linux For Real Time 7 * * * Version Details Vulnerabilities
28 OS Redhat Enterprise Linux For Real Time 8 * * * Version Details Vulnerabilities
29 OS Redhat Enterprise Linux For Real Time For Nfv 7 * * * Version Details Vulnerabilities
30 OS Redhat Enterprise Linux For Real Time For Nfv 8 * * * Version Details Vulnerabilities
31 OS Redhat Enterprise Linux For Real Time For Nfv Tus 8.2 * * * Version Details Vulnerabilities
32 OS Redhat Enterprise Linux For Real Time For Nfv Tus 8.4 * * * Version Details Vulnerabilities
33 OS Redhat Enterprise Linux For Real Time Tus 8.2 * * * Version Details Vulnerabilities
34 OS Redhat Enterprise Linux For Real Time Tus 8.4 * * * Version Details Vulnerabilities
35 OS Redhat Enterprise Linux For Scientific Computing 7.0 * * * Version Details Vulnerabilities
36 OS Redhat Enterprise Linux Server 7.0 * * * Version Details Vulnerabilities
37 OS Redhat Enterprise Linux Server Aus 7.6 * * * Version Details Vulnerabilities
38 OS Redhat Enterprise Linux Server Aus 7.7 * * * Version Details Vulnerabilities
39 OS Redhat Enterprise Linux Server Aus 8.2 * * * Version Details Vulnerabilities
40 OS Redhat Enterprise Linux Server Aus 8.4 * * * Version Details Vulnerabilities
41 OS Redhat Enterprise Linux Server For Power Little Endian Update Services For Sap Solutions 7.6 * * * Version Details Vulnerabilities
42 OS Redhat Enterprise Linux Server For Power Little Endian Update Services For Sap Solutions 8.1 * * * Version Details Vulnerabilities
43 OS Redhat Enterprise Linux Server For Power Little Endian Update Services For Sap Solutions 8.2 * * * Version Details Vulnerabilities
44 OS Redhat Enterprise Linux Server For Power Little Endian Update Services For Sap Solutions 8.4 * * * Version Details Vulnerabilities
45 OS Redhat Enterprise Linux Server Tus 7.6 * * * Version Details Vulnerabilities
46 OS Redhat Enterprise Linux Server Tus 7.7 * * * Version Details Vulnerabilities
47 OS Redhat Enterprise Linux Server Tus 8.2 * * * Version Details Vulnerabilities
48 OS Redhat Enterprise Linux Server Tus 8.4 * * * Version Details Vulnerabilities
49 OS Redhat Enterprise Linux Server Update Services For Sap Solutions 7.6 * * * Version Details Vulnerabilities
50 OS Redhat Enterprise Linux Server Update Services For Sap Solutions 7.7 * * * Version Details Vulnerabilities
51 OS Redhat Enterprise Linux Server Update Services For Sap Solutions 8.1 * * * Version Details Vulnerabilities
52 OS Redhat Enterprise Linux Server Update Services For Sap Solutions 8.2 * * * Version Details Vulnerabilities
53 OS Redhat Enterprise Linux Server Update Services For Sap Solutions 8.4 * * * Version Details Vulnerabilities
54 OS Redhat Enterprise Linux Workstation 7.0 * * * Version Details Vulnerabilities
55 Application Redhat Openstack 13 * * * Version Details Vulnerabilities

- Number Of Affected Versions By Product

Vendor Product Vulnerable Versions
Fedoraproject Fedora 2
Linux Linux Kernel 8
Redhat Enterprise Linux 1
Redhat Enterprise Linux Desktop 1
Redhat Enterprise Linux Eus 3
Redhat Enterprise Linux For Ibm Z Systems 2
Redhat Enterprise Linux For Ibm Z Systems Eus 3
Redhat Enterprise Linux For Power Big Endian 1
Redhat Enterprise Linux For Power Little Endian 2
Redhat Enterprise Linux For Power Little Endian Eus 3
Redhat Enterprise Linux For Real Time 2
Redhat Enterprise Linux For Real Time For Nfv 2
Redhat Enterprise Linux For Real Time For Nfv Tus 2
Redhat Enterprise Linux For Real Time Tus 2
Redhat Enterprise Linux For Scientific Computing 1
Redhat Enterprise Linux Server 1
Redhat Enterprise Linux Server Aus 4
Redhat Enterprise Linux Server For Power Little Endian Update Services For Sap Solutions 4
Redhat Enterprise Linux Server Tus 4
Redhat Enterprise Linux Server Update Services For Sap Solutions 5
Redhat Enterprise Linux Workstation 1
Redhat Openstack 1

- References For CVE-2021-3656

https://bugzilla.redhat.com/show_bug.cgi?id=1983988
https://git.kernel.org/pub/scm/virt/kvm/kvm.git/commit/?id=c7dfa4009965a9b2d7b329ee970eb8da0d32f0bc
https://www.openwall.com/lists/oss-security/2021/08/16/1
https://github.com/torvalds/linux/commit/c7dfa4009965a9b2d7b329ee970eb8da0d32f0bc

- Vulnerability Conditions

Vulnerability is valid if product versions listed below are used 0
Vulnerability is valid if product versions listed below are used 0
Vulnerability is valid if product versions listed below are used 0
Vulnerability is valid if product versions listed below are used 0
Vulnerability is valid if product versions listed below are used 0
Vulnerability is valid if product versions listed below are used 0
Vulnerability is valid if product versions listed below are used 0

- Metasploit Modules Related To CVE-2021-3656

There are not any metasploit modules related to this CVE entry (Please visit www.metasploit.com for more information)
CVE is a registred trademark of the MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. CWE is a registred trademark of the MITRE Corporation and the authoritative source of CWE content is MITRE's CWE web site. OVAL is a registered trademark of The MITRE Corporation and the authoritative source of OVAL content is MITRE's OVAL web site.
Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. It is the responsibility of user to evaluate the accuracy, completeness or usefulness of any information, opinion, advice or other content. EACH USER WILL BE SOLELY RESPONSIBLE FOR ANY consequences of his or her direct or indirect use of this web site. ALL WARRANTIES OF ANY KIND ARE EXPRESSLY DISCLAIMED. This site will NOT BE LIABLE FOR ANY DIRECT, INDIRECT or any other kind of loss.