# CVE-2018-1087: Privilege escalation in KVM

> An unprivileged KVM guest user can exploit a stack switch flaw to crash the guest or escalate privileges within the guest environment.

- **Severity:** High 8.0 (`CVSS:3.0/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **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:** Yes
- **Published:** 15 May 2018
- **Updated:** 5 Aug 2024
- **Also known as:** DEBIAN-CVE-2018-1087, GHSA-j658-wqr4-q3w7, UBUNTU-CVE-2018-1087

## What is CVE-2018-1087?

CVE-2018-1087 is a high-severity vulnerability in Canonical Ubuntu Linux, published on 15 May 2018. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

kernel KVM before versions kernel 4.16, kernel 4.16-rc7, kernel 4.17-rc1, kernel 4.17-rc2 and kernel 4.17-rc3 is vulnerable to a flaw in the way the Linux kernel's KVM hypervisor handled exceptions delivered after a stack switch operation via Mov SS or Pop SS instructions. During the stack switch operation, the processor did not deliver interrupts and exceptions, rather they are delivered once the first instruction after the stack switch is executed. An unprivileged KVM guest user could use this flaw to crash the guest or, potentially, escalate their privileges in the guest.

Weakness: CWE-250 (Execution with Unnecessary Privileges)

## Which versions are affected by CVE-2018-1087?

It affects 11 products.


Products: Canonical Ubuntu Linux, Debian Debian Linux, Linux kernel, Redhat Enterprise Linux, Redhat Enterprise Linux Desktop, Redhat Enterprise Linux Server, Redhat Enterprise Linux Server Aus, Redhat Enterprise Linux Server Eus, Redhat Enterprise Linux Server Tus, Redhat Enterprise Linux Virtualization, Redhat Enterprise Linux Workstation.

## How do I fix CVE-2018-1087?

Apply the vendor's patch.

## Is CVE-2018-1087 being exploited?

There is no known exploitation of CVE-2018-1087 in the wild and no public exploit code.

## Other vulnerabilities in Canonical Ubuntu Linux

- [CVE-2020-11651](https://insights.sbomify.com/CVE-2020-11651/): SaltStack Salt Authentication Bypass (critical 9.8, exploited in the wild)
- [CVE-2020-7247](https://insights.sbomify.com/CVE-2020-7247/): OpenSMTPD Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2019-16928](https://insights.sbomify.com/CVE-2019-16928/): Exim Out-of-bounds Write (critical 9.8, exploited in the wild)
- [CVE-2018-6789](https://insights.sbomify.com/CVE-2018-6789/): Exim Buffer Overflow (critical 9.8, exploited in the wild)
- [CVE-2015-2590](https://insights.sbomify.com/CVE-2015-2590/): Oracle Java SE and Java SE Embedded Remote Code Execution (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-1087 and fix it if it is affected.

What it is: CVE-2018-1087 is a high-severity vulnerability in Canonical Ubuntu Linux, published on 15 May 2018. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2018-1087 in the wild and no public exploit code.

Affected product: Canonical Ubuntu Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2018-1087/ (Markdown: https://insights.sbomify.com/CVE-2018-1087/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-1087
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-1087
- OSV: https://osv.dev/vulnerability/CVE-2018-1087

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-1087/
Summaries are generated and may contain mistakes; the official description above is the record.