# CVE-2019-5747: Information disclosure in n/a

> A remote attacker can leak sensitive stack information via crafted DHCP messages in BusyBox udhcp components, affecting embedded and Linux systems.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 9 Jan 2019
- **Updated:** 9 Jun 2025
- **Also known as:** ALPINE-CVE-2019-5747, DEBIAN-CVE-2019-5747, GHSA-h49r-cwwr-2hv6, UBUNTU-CVE-2019-5747

## What is CVE-2019-5747?

CVE-2019-5747 is a high-severity vulnerability in Canonical Ubuntu Linux, published on 9 Jan 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An issue was discovered in BusyBox through 1.30.0. An out of bounds read in udhcp components (consumed by the DHCP client, server, and/or relay) might allow a remote attacker to leak sensitive information from the stack by sending a crafted DHCP message. This is related to assurance of a 4-byte length when decoding DHCP_SUBNET. NOTE: this issue exists because of an incomplete fix for CVE-2018-20679.

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2019-5747?

It affects 2 products.


Products: Busybox Busybox, Canonical Ubuntu Linux.

## How do I fix CVE-2019-5747?

Apply the vendor's patch.

## Is CVE-2019-5747 being exploited?

There is no known exploitation of CVE-2019-5747 in the wild and no public exploit code.

## Other vulnerabilities in Canonical Ubuntu Linux

- [CVE-2022-48174](https://insights.sbomify.com/CVE-2022-48174/): Memory corruption in n/a (critical 9.8)
- [CVE-2021-42377](https://insights.sbomify.com/CVE-2021-42377/): Memory corruption in busybox (critical 9.8)
- [CVE-2016-2148](https://insights.sbomify.com/CVE-2016-2148/): Memory corruption in n/a (critical 9.8)
- [CVE-2022-28391](https://insights.sbomify.com/CVE-2022-28391/): Command injection in n/a (high 8.8)
- [CVE-2017-16544](https://insights.sbomify.com/CVE-2017-16544/): Code injection in n/a (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-5747 and fix it if it is affected.

What it is: CVE-2019-5747 is a high-severity vulnerability in Canonical Ubuntu Linux, published on 9 Jan 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2019-5747 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-2019-5747/ (Markdown: https://insights.sbomify.com/CVE-2019-5747/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-5747
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-5747
- OSV: https://osv.dev/vulnerability/CVE-2019-5747

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-5747/
Summaries are generated and may contain mistakes; the official description above is the record.