# CVE-2019-19039: Information disclosure in n/a

> Local users can read sensitive register values via dmesg due to excessive logging in the BTRFS filesystem driver.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 21 Nov 2019
- **Updated:** 5 Aug 2024
- **Also known as:** DEBIAN-CVE-2019-19039, GHSA-g3r9-j55g-jg8j, UBUNTU-CVE-2019-19039

## What is CVE-2019-19039?

CVE-2019-19039 is a medium-severity vulnerability in Canonical Ubuntu Linux, published on 21 Nov 2019. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

__btrfs_free_extent in fs/btrfs/extent-tree.c in the Linux kernel through 5.3.12 calls btrfs_print_leaf in a certain ENOENT case, which allows local users to obtain potentially sensitive information about register values via the dmesg program. NOTE: The BTRFS development team disputes this issues as not being a vulnerability because “1) The kernel provide facilities to restrict access to dmesg - dmesg_restrict=1 sysctl option. So it's really up to the system administrator to judge whether dmesg access shall be disallowed or not. 2) WARN/WARN_ON are widely used macros in the linux kernel. If this CVE is considered valid this would mean there are literally thousands CVE lurking in the kernel - something which clearly is not the case.

Weakness: CWE-532 (Insertion of Sensitive Information into Log File)

## Which versions are affected by CVE-2019-19039?

It affects 3 products.


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

## How do I fix CVE-2019-19039?

No fix published yet.

## Is CVE-2019-19039 being exploited?

There is no known exploitation of CVE-2019-19039 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-2019-19039 and fix it if it is affected.

What it is: CVE-2019-19039 is a medium-severity vulnerability in Canonical Ubuntu Linux, published on 21 Nov 2019. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2019-19039 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-2019-19039/ (Markdown: https://insights.sbomify.com/CVE-2019-19039/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-19039
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-19039
- OSV: https://osv.dev/vulnerability/CVE-2019-19039

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-19039/
Summaries are generated and may contain mistakes; the official description above is the record.