Description
A flaw was found in Linux kernel's KVM virtualization subsystem. The VMX code does not restore the GDT.LIMIT to the previous host value, but instead sets it to 64KB. With a corrupted GDT limit a host's userspace code has an ability to place malicious entries in the GDT, particularly to the per-cpu variables. An attacker can use this to escalate their privileges.
CVSS breakdown
CVSS 3.0
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Affected products
- Unknown / kerneln/a – n/a
References
- MISChttp://www.securityfocus.com/bid/104905
- VENDOR_ADVISORYhttps://access.redhat.com/errata/RHSA-2018:2393
- VENDOR_ADVISORYhttps://access.redhat.com/errata/RHSA-2018:2390
- VENDOR_ADVISORYhttps://access.redhat.com/errata/RHSA-2018:2391
- VENDOR_ADVISORYhttps://access.redhat.com/errata/RHSA-2018:2392
- VENDOR_ADVISORYhttps://access.redhat.com/errata/RHSA-2018:2394
- VENDOR_ADVISORYhttps://www.oracle.com/security-alerts/cpujul2020.html
- VENDOR_ADVISORYhttps://www.oracle.com/technetwork/security-advisory/cpuapr2019-5072813.html
- MISChttps://help.ecostruxureit.com/display/public/UADCE725/Security+fixes+in+StruxureWare+Data+Center+Expert+v7.6.0
- MISChttps://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=3444d7da1839b851eefedd372978d8a982316c36
- MISChttps://bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-10901