An issue was discovered in BusyBox before 1.30.0.

Published 7 y ago 2019-01-09 · modified 4 mo ago 2026-06-17 · JSON

CVSS

7.5

v3.1 · CNA

CISA KEV

not known exploited

EPSS

7.7%

percentile 95%

Public exploits

none known

An issue was discovered in BusyBox before 1.30.0. An out of bounds read in udhcp components (consumed by the DHCP server, client, and relay) allows a remote attacker to leak sensitive information from the stack by sending a crafted DHCP message. This is related to verification in udhcp_get_option() in networking/udhcp/common.c that 4-byte options are indeed 4 bytes.

CISA SSVC assessment

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 16 mo ago 2025-06-09

Exploit prediction (EPSS)

7.69% probability of exploitation in the next 30 days, higher than 95% of all scored CVEs.

CVSS scores

Assigned by	Version	Score	Vector
CISA ADP	3.1	7.5	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N`
CNA	3.1	7.5	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N`
NVD	3.0	7.5	`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N`
NVD	2.0	5.0	`AV:N/AC:L/Au:N/C:P/I:N/A:N`

Classification

Weakness

CWE-125 Out-of-bounds Read

References

git.busybox.net /busybox/commit/?id=6d3b4bb24da9a07c263f3c1acf8df85382ff562c · x_refsource_MISC, x_transferred
busybox.net /news.html · x_refsource_MISC, x_transferred
bugs.busybox.net /show_bug.cgi?id=11506 · x_refsource_MISC, x_transferred
usn.ubuntu.com /3935-1/ · vendor-advisory, x_refsource_UBUNTU, x_transferred
seclists.org /fulldisclosure/2019/Sep/7 · mailing-list, x_refsource_FULLDISC, x_transferred
seclists.org /bugtraq/2019/Sep/7 · mailing-list, x_refsource_BUGTRAQ, x_transferred
packetstormsecurity.com /files/154361/Cisco-Device-Hardcoded-Credentials-GNU-glibc-BusyBox.html · x_refsource_MISC, x_transferred

Sources

CVE List: CVE-2018-20679
NVD: CVE-2018-20679

vulnwire keeps one entry per vulnerability: the CVE id wins, then GHSA; records that alias each other are merged. Machine-readable: JSON.