CVE-2018-12633 Race condition in n/a

What is CVE-2018-12633?

CVE-2018-12633 is a medium-severity vulnerability in Linux kernel, published on 22 Jun 2018. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

An issue was discovered in the Linux kernel through 4.17.2. vbg_misc_device_ioctl() in drivers/virt/vboxguest/vboxguest_linux.c reads the same user data twice with copy_from_user. The header part of the user data is double-fetched, and a malicious user thread can tamper with the critical variables (hdr.size_in and hdr.size_out) in the header between the two fetches because of a race condition, leading to severe kernel errors, such as buffer over-accesses. This bug can cause a local denial of service and information leakage.

Weakness: CWE-362

Which versions are affected by CVE-2018-12633?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2018-12633?

Apply the vendor's patch.

Is CVE-2018-12633 being exploited?

There is no known exploitation of CVE-2018-12633 in the wild and no public exploit code.

Public exploit code: 1 proofs of concept on GitHub.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2018-12633, GHSA-9rwp-mqvh-8g6q, UBUNTU-CVE-2018-12633.