# CVE-2018-1000204: Information disclosure in n/a

> A local attacker with specific capabilities can read kernel heap memory via a SCSI ioctl, potentially exposing sensitive data.

- **Severity:** Medium 5.3 (`CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 26 Jun 2018
- **Updated:** 5 Aug 2024
- **Also known as:** DEBIAN-CVE-2018-1000204, GHSA-xrfx-4wv5-78ww, UBUNTU-CVE-2018-1000204

## What is CVE-2018-1000204?

CVE-2018-1000204 is a medium-severity vulnerability in Canonical Ubuntu Linux, published on 26 Jun 2018. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Linux Kernel version 3.18 to 4.16 incorrectly handles an SG_IO ioctl on /dev/sg0 with dxfer_direction=SG_DXFER_FROM_DEV and an empty 6-byte cmdp. This may lead to copying up to 1000 kernel heap pages to the userspace. This has been fixed upstream in https://github.com/torvalds/linux/commit/a45b599ad808c3c982fdcdc12b0b8611c2f92824 already. The problem has limited scope, as users don't usually have permissions to access SCSI devices. On the other hand, e.g. the Nero user manual suggests doing `chmod o+r+w /dev/sg*` to make the devices accessible. NOTE: third parties dispute the relevance of this report, noting that the requirement for an attacker to have both the CAP_SYS_ADMIN and CAP_SYS_RAWIO capabilities makes it "virtually impossible to exploit.

## Which versions are affected by CVE-2018-1000204?

It affects 3 products.


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

## How do I fix CVE-2018-1000204?

Apply the vendor's patch.

## Is CVE-2018-1000204 being exploited?

There is no known exploitation of CVE-2018-1000204 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-2018-1000204 and fix it if it is affected.

What it is: CVE-2018-1000204 is a medium-severity vulnerability in Canonical Ubuntu Linux, published on 26 Jun 2018. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2018-1000204 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-2018-1000204/ (Markdown: https://insights.sbomify.com/CVE-2018-1000204/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-1000204
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-1000204
- OSV: https://osv.dev/vulnerability/CVE-2018-1000204

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-1000204/
Summaries are generated and may contain mistakes; the official description above is the record.