CVE-2019-5747 Information disclosure in n/a

High 7.5 Published 9 Jan 2019 Updated 9 Jun 2025

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

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: Available

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

Which versions are affected by CVE-2019-5747?

It affects 2 products.

Products include 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.

All Canonical Ubuntu Linux vulnerabilities

Sources

Also known as ALPINE-CVE-2019-5747, DEBIAN-CVE-2019-5747, GHSA-h49r-cwwr-2hv6, UBUNTU-CVE-2019-5747.