Vulnerability Description
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.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux Kernel | >= 2.6.30, < 4.4.282 |
| Redhat | Enterprise Linux | 7.0 |
| Debian | Debian Linux | 9.0 |
Related Weaknesses (CWE)
References
- http://packetstormsecurity.com/files/165477/Kernel-Live-Patch-Security-Notice-LSExploitThird Party AdvisoryVDB Entry
- https://bugzilla.redhat.com/show_bug.cgi?id=1983686Issue TrackingPatchThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2021/10/msg00010.htmlMailing ListThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2021/12/msg00012.htmlMailing ListThird Party Advisory
- https://www.openwall.com/lists/oss-security/2021/08/16/1Mailing ListPatchThird Party Advisory
- http://packetstormsecurity.com/files/165477/Kernel-Live-Patch-Security-Notice-LSExploitThird Party AdvisoryVDB Entry
- https://bugzilla.redhat.com/show_bug.cgi?id=1983686Issue TrackingPatchThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2021/10/msg00010.htmlMailing ListThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2021/12/msg00012.htmlMailing ListThird Party Advisory
- https://www.openwall.com/lists/oss-security/2021/08/16/1Mailing ListPatchThird Party Advisory
FAQ
What is CVE-2021-3653?
CVE-2021-3653 is a vulnerability with a CVSS score of 8.8 (HIGH). 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 nes...
How severe is CVE-2021-3653?
CVE-2021-3653 has been rated HIGH with a CVSS base score of 8.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2021-3653?
Check the references section above for vendor advisories and patch information. Affected products include: Linux Linux Kernel, Redhat Enterprise Linux, Debian Debian Linux.