CVE-2018-10853: High severity Canonical Ubuntu Linux vulnerability
A flaw was found in the way Linux kernel KVM hypervisor before 4.18 emulated instructions such as sgdt/sidt/fxsave/fxrstor. It did not check current privilege(CPL) level while emulating unprivileged instructions. An unprivileged guest user/process could use this flaw to potentially escalate privileges inside guest.
Other sources
A flaw was found in the way Linux kernel KVM hypervisor emulated instructions such as sgdt/sidt/fxsave/fxrstor. It did not check current privilege(CPL) level while emulating unprivileged instructions.
An unprivileged guest user/process could use this flaw to potentially escalate privileges inside guest.
Upstream patch: --------------- -> https://git.kernel.org/linus/3c9fa24ca7c9c47605672916491f79e8ccacb9e6
Issue introduced in: (kernel v4.10+) -------------------- -> https://git.kernel.org/linus/129a72a0d3c8e139a04512325384fe5ac119e74
Reference: ---------- -> http://www.openwall.com/lists/oss-security/2018/09/02/1
— Red Hat
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
redhat/kernel-rtto a version that resolves this vulnerability.Fixed in 0:3.10.0-1062.rt56.1022.el7 - Upgrade
Upgrade
redhat/kernelto a version that resolves this vulnerability.Fixed in 0:3.10.0-1062.el7 - Upgrade
Upgrade
redhat/kernelto a version that resolves this vulnerability.Fixed in 0:3.10.0-693.62.1.el7 - Upgrade
Upgrade
redhat/kernelto a version that resolves this vulnerability.Fixed in 0:3.10.0-862.46.1.el7 - Upgrade
Upgrade
redhat/kernelto a version that resolves this vulnerability.Fixed in 0:3.10.0-957.43.1.el7 - Upgrade
Upgrade
redhat/kernelto a version that resolves this vulnerability.Fixed in 4.18 - Upgrade
Upgrade
debian/linuxto a version that resolves this vulnerability.Fixed in 6.1.176-1Fixed in 6.1.187-1Fixed in 6.12.107-1Fixed in 6.12.111-1Fixed in 7.2.9-1Fixed in 7.2.10-1 - Upgrade
Upgrade
Linux kernel KVM hypervisorto a version that resolves this vulnerability.Fixed in 4.18 - Operational
Reboot/refresh KVM-enabled hosts after applying the upstream Linux kernel patches so the corrected KVM instruction emulation code is active.
Event History
Parent advisories
This vulnerability appears in the following advisories.
Frequently Asked Questions
What is the severity of CVE-2018-10853?
CVE-2018-10853 has a medium severity rating due to its potential for privilege escalation.
How do I fix CVE-2018-10853?
To fix CVE-2018-10853, upgrade to kernel version 4.18 or later as specified in the security advisories from the affected distributions.
Which systems are affected by CVE-2018-10853?
CVE-2018-10853 affects various versions of the Linux kernel, particularly those prior to 4.18, including specific versions in Red Hat, Ubuntu, and Debian.
What impact does CVE-2018-10853 have on a system?
CVE-2018-10853 could allow an unprivileged guest user or process to exploit the vulnerability for privilege escalation on the host.
Is CVE-2018-10853 a guest-to-host attack vector?
Yes, CVE-2018-10853 allows a guest user to potentially escalate privileges to the host system.