CVE-2018-18281 Race condition in n/a

High 7.8 Published 30 Oct 2018 Updated 5 Aug 2024

A race condition in the Linux kernel mremap syscall allows attackers to access freed physical memory, potentially leading to privilege escalation or data exposure.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Local or same network only
Victim action needed: Not needed
Fix: Available

What is CVE-2018-18281?

CVE-2018-18281 is a high-severity vulnerability in Canonical Ubuntu Linux, published on 30 Oct 2018. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

Since Linux kernel version 3.2, the mremap() syscall performs TLB flushes after dropping pagetable locks. If a syscall such as ftruncate() removes entries from the pagetables of a task that is in the middle of mremap(), a stale TLB entry can remain for a short time that permits access to a physical page after it has been released back to the page allocator and reused. This is fixed in the following kernel versions: 4.9.135, 4.14.78, 4.18.16, 4.19.

Weakness: CWE-459

Which versions are affected by CVE-2018-18281?

It affects 3 products.

Products include Canonical Ubuntu Linux, Debian Debian Linux, Linux kernel.

How do I fix CVE-2018-18281?

Apply the vendor's patch.

Is CVE-2018-18281 being exploited?

There is no known exploitation of CVE-2018-18281 in the wild and no public exploit code.

All Canonical Ubuntu Linux vulnerabilities

Sources

Also known as DEBIAN-CVE-2018-18281, GHSA-gffw-ppmc-p7r6, UBUNTU-CVE-2018-18281.