Bugzilla will be upgraded to version 5.0 on a still to be determined date in the near future. The original upgrade date has been delayed.
First Last Prev Next    This bug is not in your last search results.
Bug 1595143 - (CVE-2018-12904) CVE-2018-12904 kernel: kvm: nVMX: missing privilege check allows privilege escalation in nested virtualization
CVE-2018-12904 kernel: kvm: nVMX: missing privilege check allows privilege es...
Status: NEW
Product: Security Response
Classification: Other
Component: vulnerability (Show other bugs)
unspecified
All Linux
medium Severity medium
: ---
: ---
Assigned To: Red Hat Product Security
impact=moderate,public=20180612,repor...
: Security
Depends On: 1595145 1595146
Blocks: 1595148
  Show dependency tree / graph
 
Reported: 2018-06-26 04:42 EDT by Adam Mariš
Modified: 2018-08-29 15:15 EDT (History)
44 users (show)

See Also:
Fixed In Version: kernel 4.17.2
Doc Type: If docs needed, set a value
Doc Text:
Story Points: ---
Clone Of:
Environment:
Last Closed:
Type: ---
Regression: ---
Mount Type: ---
Documentation: ---
CRM:
Verified Versions:
Category: ---
oVirt Team: ---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---

Attachments (Terms of Use)
Add an attachment (proposed patch, testcase, etc.)

  None (edit)
Description Adam Mariš 2018-06-26 04:42:45 EDT 
It was found that KVM virtualizing another hypervisor as L1 VM does not verify that VMX instructions from L1 VM (which trigger a VM exit and are emulated by L0 KVM) are coming from ring 0. This means that a normal user space program running in the L1 VM can trigger KVMs VMX emulation which gives a large number of privilege escalation vectors. This issue happens only if L2 guest is running, since VMX emulation code checks for the guests CR4.VMXE value.

This allows attacker in L2 guest to break out e.g. by exploiting a bug in L1 qemu process and using this bug for privilege escalation on the L1 system.

Bug report:

https://bugs.chromium.org/p/project-zero/issues/detail?id=1589

Upstream patch:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/arch/x86/kvm?id=727ba748e110b4de50d142edca9d6a9b7e6111d8
Comment 1 Adam Mariš 2018-06-26 04:43:47 EDT 
Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1595146]
Comment 3 Adam Mariš 2018-06-27 08:30:59 EDT 
CVE known via:

http://seclists.org/oss-sec/2018/q2/246
Comment 4 Prasad J Pandit 2018-08-29 14:54:47 EDT 
Statement:

This issue does not affect the versions of the kernel package as shipped with
Red Hat Enterprise Linux 5, 6, 7 and Red Hat Enterprise MRG 2.
Note You need to log in before you can comment on or make changes to this bug.
First Last Prev Next    This bug is not in your last search results.