Vulnerability Monitor

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CVE-2018-20679

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.

Security Impact Summary

This vulnerability carries a HIGH severity rating with a CVSS v3.1 score of 7.5, indicating it can be exploited remotely over the network with relatively low complexity without requiring user interaction and does not require pre-existing privileges . The vulnerability impacts confidentiality (data exposure), for affected systems. Impacting 2 products from busybox, from canonical organizations running these solutions should prioritize assessment and patching.

Historical Context

First disclosed in 2019, this vulnerability was reported during a period defined by widespread IoT adoption challenges, mobile security concerns, and the emergence of advanced persistent threat (APT) techniques. Contemporary mitigation strategies focused on secure development practices and third-party component vetting.

Published

2019-01-09T16:29:00.273

Last Modified

2025-06-09T16:15:29.090

Status

Modified

Source

[email protected]

Severity

CVSSv3.1: 7.5 (HIGH)

CVSSv2 Vector

AV:N/AC:L/Au:N/C:P/I:N/A:N

Access Vector: NETWORK
Access Complexity: LOW
Authentication: NONE
Confidentiality Impact: PARTIAL
Integrity Impact: NONE
Availability Impact: NONE

Exploitability Score

10.0

Impact Score

2.9

Weaknesses

Type: Primary
CWE-125
Type: Secondary
CWE-125

Affected Vendors & Products

Type	Vendor	Product	Version/Range	Vulnerable?
Application	busybox	busybox	< 1.30.0	Yes
Operating System	canonical	ubuntu_linux	14.04	Yes
Operating System	canonical	ubuntu_linux	16.04	Yes
Operating System	canonical	ubuntu_linux	18.04	Yes
Operating System	canonical	ubuntu_linux	18.10	Yes

References

http://packetstormsecurity.com/files/154361/Cisco-Device-Hardcoded-Credentials-GNU-glibc-BusyBox.html ([email protected])
http://seclists.org/fulldisclosure/2019/Sep/7 ([email protected])
https://bugs.busybox.net/show_bug.cgi?id=11506 Exploit, Issue Tracking, Third Party Advisory ([email protected])
https://busybox.net/news.html Release Notes, Third Party Advisory ([email protected])
https://git.busybox.net/busybox/commit/?id=6d3b4bb24da9a07c263f3c1acf8df85382ff562c Patch, Third Party Advisory ([email protected])
https://seclists.org/bugtraq/2019/Sep/7 ([email protected])
https://usn.ubuntu.com/3935-1/ Third Party Advisory ([email protected])
http://packetstormsecurity.com/files/154361/Cisco-Device-Hardcoded-Credentials-GNU-glibc-BusyBox.html (af854a3a-2127-422b-91ae-364da2661108)
http://seclists.org/fulldisclosure/2019/Sep/7 (af854a3a-2127-422b-91ae-364da2661108)
https://bugs.busybox.net/show_bug.cgi?id=11506 Exploit, Issue Tracking, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://busybox.net/news.html Release Notes, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://git.busybox.net/busybox/commit/?id=6d3b4bb24da9a07c263f3c1acf8df85382ff562c Patch, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://seclists.org/bugtraq/2019/Sep/7 (af854a3a-2127-422b-91ae-364da2661108)
https://usn.ubuntu.com/3935-1/ Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)

How SecUtils Interprets This CVE

SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For busybox's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.