Vulnerability identifier: #VU13516

Vulnerability risk: Low

CVSSv3.1: 7 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C]

CVE-ID: CVE-2018-12904

CWE-ID: CWE-264

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
Linux kernel
Operating systems & Components / Operating system

Vendor: Linux Foundation

Description

The vulnerability allows a local attacker to gain elevated privileges on the target system.

The vulnerability exists due to insufficient checking of the current privilege level (CPL) for Virtual Machine Extensions (VMX) instructions by the arch/x86/kvm/vmx.c source code file when nested virtualization is used. A local attacker can cause a targeted L1 Kernel-based Virtual Machine (KVM) guest to exit and gain elevated privileges on the targeted L1 system, which could be used to conduct further attacks.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Linux kernel: 4.17.1 - 4.17.2, 4.16 - 4.16.18, 4.15 - 4.15.18

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External links
http://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=727ba748e110b4de50d142edca9d6a9b7e6111d8

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Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.