8.1 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
6.8 Medium
CVSS2
Access Vector
NETWORK
Access Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:N/AC:M/Au:N/C:P/I:P/A:P
0.049 Low
EPSS
Percentile
92.6%
Issue Overview:
A use-after-free vulnerability was found in the way the Linux kernel’s KVM hypervisor emulates a preemption timer for L2 guests when nested (=1) virtualization is enabled. This high resolution timer(hrtimer) runs when a L2 guest is active. After VM exit, the sync_vmcs12() timer object is stopped. The use-after-free occurs if the timer object is freed before calling sync_vmcs12() routine. A guest user/process could use this flaw to crash the host kernel resulting in a denial of service or, potentially, gain privileged access to a system. (CVE-2019-7221)
A use-after-free vulnerability was found in the way the Linux kernel’s KVM hypervisor implements its device control API. While creating a device via kvm_ioctl_create_device(), the device holds a reference to a VM object, later this reference is transferred to the caller’s file descriptor table. If such file descriptor was to be closed, reference count to the VM object could become zero, potentially leading to a use-after-free issue. A user/process could use this flaw to crash the guest VM resulting in a denial of service issue or, potentially, gain privileged access to a system. (CVE-2019-6974)
An information leakage issue was found in the way Linux kernel’s KVM hypervisor handled page fault exceptions while emulating instructions like VMXON, VMCLEAR, VMPTRLD, and VMWRITE with memory address as an operand. It occurs if the operand is a mmio address, as the returned exception object holds uninitialized stack memory contents. A guest user/process could use this flaw to leak host’s stack memory contents to a guest. (CVE-2019-7222)
Affected Packages:
kernel
Issue Correction:
Run yum update kernel to update your system.
New Packages:
i686:
kernel-4.14.101-75.76.amzn1.i686
kernel-tools-devel-4.14.101-75.76.amzn1.i686
kernel-tools-debuginfo-4.14.101-75.76.amzn1.i686
kernel-debuginfo-4.14.101-75.76.amzn1.i686
kernel-headers-4.14.101-75.76.amzn1.i686
perf-debuginfo-4.14.101-75.76.amzn1.i686
kernel-tools-4.14.101-75.76.amzn1.i686
perf-4.14.101-75.76.amzn1.i686
kernel-debuginfo-common-i686-4.14.101-75.76.amzn1.i686
kernel-devel-4.14.101-75.76.amzn1.i686
src:
kernel-4.14.101-75.76.amzn1.src
x86_64:
kernel-debuginfo-common-x86_64-4.14.101-75.76.amzn1.x86_64
perf-debuginfo-4.14.101-75.76.amzn1.x86_64
kernel-tools-debuginfo-4.14.101-75.76.amzn1.x86_64
kernel-tools-devel-4.14.101-75.76.amzn1.x86_64
kernel-headers-4.14.101-75.76.amzn1.x86_64
kernel-debuginfo-4.14.101-75.76.amzn1.x86_64
kernel-4.14.101-75.76.amzn1.x86_64
perf-4.14.101-75.76.amzn1.x86_64
kernel-devel-4.14.101-75.76.amzn1.x86_64
kernel-tools-4.14.101-75.76.amzn1.x86_64
Red Hat: CVE-2019-6974, CVE-2019-7221, CVE-2019-7222
Mitre: CVE-2019-6974, CVE-2019-7221, CVE-2019-7222
8.1 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
6.8 Medium
CVSS2
Access Vector
NETWORK
Access Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:N/AC:M/Au:N/C:P/I:P/A:P
0.049 Low
EPSS
Percentile
92.6%