CVE-2017-1000405

What it is

The Linux Kernel versions 2.6.38 through 4.14 have a problematic use of pmd_mkdirty() in the touch_pmd() function inside the THP implementation. touch_pmd() can be reached by get_user_pages(). In such case, the pmd will become dirty. This scenario breaks the new can_follow_write_pmd()'s logic - pmd can become dirty without going through a COW cycle. This bug is not as severe as the original "Dirty cow" because an ext4 file (or any other regular file) cannot be mapped using THP. Nevertheless, it does allow us to overwrite read-only huge pages. For example, the zero huge page and sealed shmem files can be overwritten (since their mapping can be populated using THP). Note that after the first write page-fault to the zero page, it will be replaced with a new fresh (and zeroed) thp.

At a glance

Exploitability

Can be exploited locally on the machine with a low-privilege account. High risk of data exposure, data tampering, service disruption.

Exploit odds

2.8% chance of exploitation in the next 30 days (EPSS).

Fix

No patch or advisory is linked yet. Look at mitigations or restrict exposure.

Timeline

1. 2017-11-30 22:29 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 00:59 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 2.8% in the next 30 days (EPSS).
• Severity: 7.0 HIGH (CVSS).
• Fix: none linked yet, which raises it.

Details

Published

2017-11-30 22:29 UTC

Last modified

2026-06-17 00:59 UTC

Exploit probability

2.8% · EPSS, next 30 days

Weakness

CWE-362 · Race condition

Record status

Modified

Affected

• Linux Kernel < 3.3
• Linux Kernel < 3.11
• Linux Kernel < 3.13
• Linux Kernel < 3.16.52
• Linux Kernel < 3.18.86
• Linux Kernel < 4.1.48
• Linux Kernel < 4.4.104
• Linux Kernel < 4.9.67

Attack profile CVSS 3.1 · 7.0

Attack vector

Local

Complexity

High

Privileges needed

Low

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2017-1000405.md and follow it. Check whether this project is affected by CVE-2017-1000405. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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