Description
A flaw was found in the Linux kernel before version 4.12 in the way the KVM module processed the trap flag(TF) bit in EFLAGS during emulation of the syscall instruction, which leads to a debug exception(#DB) being raised in the guest stack. A user/process inside a guest could use this flaw to potentially escalate their privileges inside the guest. Linux guests are not affected by this.
CVSS breakdown
CVSS 3.0
Attack Vector
Adjacent
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
Low
Affected products
- Unknown / kernel4.12 – 4.12
References
- VENDOR_ADVISORYhttps://access.redhat.com/errata/RHSA-2018:0412
- VENDOR_ADVISORYhttps://access.redhat.com/articles/3290921
- VENDOR_ADVISORYhttps://usn.ubuntu.com/3619-2/
- VENDOR_ADVISORYhttps://access.redhat.com/errata/RHSA-2018:0395
- VENDOR_ADVISORYhttps://usn.ubuntu.com/3754-1/
- MISChttp://www.securitytracker.com/id/1038782
- MISChttps://bugzilla.redhat.com/show_bug.cgi?id=CVE-2017-7518
- MAILING_LISThttp://www.openwall.com/lists/oss-security/2017/06/23/5
- VENDOR_ADVISORYhttps://usn.ubuntu.com/3619-1/
- VENDOR_ADVISORYhttps://www.debian.org/security/2017/dsa-3981
- MISChttps://www.spinics.net/lists/kvm/msg151817.html
- MISChttp://www.securityfocus.com/bid/99263