CVE-2018-16882 Use after free in kernel:
A guest user can trigger a use-after-free in the Linux kernel KVM hypervisor to crash the host or gain privileged access.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2018-16882?
CVE-2018-16882 is a medium-severity use after free vulnerability in Canonical Ubuntu Linux, published on 3 Jan 2019. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
A use-after-free issue was found in the way the Linux kernel's KVM hypervisor processed posted interrupts when nested(=1) virtualization is enabled. In nested_get_vmcs12_pages(), in case of an error while processing posted interrupt address, it unmaps the 'pi_desc_page' without resetting 'pi_desc' descriptor address, which is later used in pi_test_and_clear_on(). A guest user/process could use this flaw to crash the host kernel resulting in DoS or potentially gain privileged access to a system. Kernel versions before 4.14.91 and before 4.19.13 are vulnerable.
Weakness: CWE-416
Which versions are affected by CVE-2018-16882?
It affects 2 products.
Products include Canonical Ubuntu Linux, Linux kernel.
How do I fix CVE-2018-16882?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2018-16882 being exploited?
There is no known exploitation of CVE-2018-16882 in the wild and no public exploit code.
Other vulnerabilities in Canonical Ubuntu Linux
Sources
Also known as DEBIAN-CVE-2018-16882, GHSA-4wh7-45g5-wcc8, UBUNTU-CVE-2018-16882.