PT-2018-10153 · Linux+4 · Linux Kernel+4
Andy Lutomirski
·
Published
2018-05-08
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Updated
2019-10-09
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CVE-2018-1087
CVSS v3.1
8.0
High
| Vector | AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
Name of the Vulnerable Software and Affected Versions
Linux kernel versions prior to 4.16
Linux kernel versions 4.16-rc7 and earlier
Linux kernel versions 4.17-rc1 through 4.17-rc3
Description
The issue is related to a flaw in the way the Linux kernel's KVM hypervisor handled exceptions delivered after a stack switch operation via Mov SS or Pop SS instructions. During the stack switch operation, the processor did not deliver interrupts and exceptions, rather they are delivered once the first instruction after the stack switch is executed. An unprivileged KVM guest user could use this flaw to crash the guest or, potentially, escalate their privileges in the guest.
Recommendations
For Linux kernel versions prior to 4.16, update to version 4.16 or later.
For Linux kernel versions 4.16-rc7 and earlier, update to a version later than 4.16-rc7.
For Linux kernel versions 4.17-rc1 through 4.17-rc3, update to a version later than 4.17-rc3.
As a temporary workaround, consider restricting access to the KVM hypervisor to minimize the risk of exploitation.
Fix
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Weakness Enumeration
Related Identifiers
Affected Products
Centos
Linux Kernel
Red Hat
Suse
Ubuntu