Vulnerability Details : CVE-2021-3653
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 "int_ctl" field, this issue could allow a malicious L1 to enable AVIC support (Advanced Virtual Interrupt Controller) 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. This flaw affects Linux kernel versions prior to 5.14-rc7.
Exploit prediction scoring system (EPSS) score for CVE-2021-3653
Probability of exploitation activity in the next 30 days: 0.06%
Percentile, the proportion of vulnerabilities that are scored at or less: ~ 21 % EPSS Score History EPSS FAQ
CVSS scores for CVE-2021-3653
Base Score | Base Severity | CVSS Vector | Exploitability Score | Impact Score | Score Source |
---|---|---|---|---|---|
6.1
|
MEDIUM | AV:L/AC:L/Au:N/C:P/I:P/A:C |
3.9
|
8.5
|
NIST |
8.8
|
HIGH | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H |
2.0
|
6.0
|
NIST |
CWE ids for CVE-2021-3653
-
The product does not perform an authorization check when an actor attempts to access a resource or perform an action.Assigned by:
- nvd@nist.gov (Secondary)
- secalert@redhat.com (Primary)
References for CVE-2021-3653
-
https://www.openwall.com/lists/oss-security/2021/08/16/1
oss-security - [CVE-2021-3653, CVE-2021-3656] SVM nested virtualization issues in KVMMailing List;Patch;Third Party Advisory
-
https://lists.debian.org/debian-lts-announce/2021/12/msg00012.html
[SECURITY] [DLA 2843-1] linux security updateMailing List;Third Party Advisory
-
http://packetstormsecurity.com/files/165477/Kernel-Live-Patch-Security-Notice-LSN-0083-1.html
Kernel Live Patch Security Notice LSN-0083-1 ≈ Packet StormExploit;Third Party Advisory;VDB Entry
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https://bugzilla.redhat.com/show_bug.cgi?id=1983686
1983686 – (CVE-2021-3653) CVE-2021-3653 kernel: SVM nested virtualization issue in KVM (AVIC support)Issue Tracking;Patch;Third Party Advisory
-
https://lists.debian.org/debian-lts-announce/2021/10/msg00010.html
[SECURITY] [DLA 2785-1] linux-4.19 security updateMailing List;Third Party Advisory
Products affected by CVE-2021-3653
- cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:5.14:rc1:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:5.14:rc2:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:5.14:rc3:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:5.14:rc4:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:5.14:rc5:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:5.14:rc6:*:*:*:*:*:*