CVE-2018-20679: busybox Out-of-bounds Read
Vulnerability summary
CVE-2018-20679 is a high (CVSS 7.5) Out-of-bounds Read vulnerability in busybox. EPSS estimates a 7.69% chance of exploitation in the next 30 days, higher than 94.5% of scored vulnerabilities. 1 public exploit is recorded.
Advisory lineage
Upstream 0 · Downstream 10 · Related 10Timeline
- 09-01-2019PublishedVulnerability first disclosed.
- 09-06-2025Last modifiedVulnerability information updated.
Description
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.
CVSS metrics
8 scores · 5 sources · 3 versions- NVDNIST7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- OSV · AlpineEcosystem advisory · calculated7.5HighCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- OSV · DebianEcosystem advisory · calculated7.5HighCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS trend
Probability
7.69%
Chance of exploitation in the next 30 days
Percentile
95%
Versus all other CVEs
30-day change
0.00 pp
From 7.69% on 18-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
1 foundExploit Reference (bugs.busybox.net)
Maturity: unknown
Weaknesses
CWE · root causeAffected systems
Alpine1 product
- busybox< 1.29.3-r10
Busybox1 product
- busybox< 1.30.0
Canonical1 product
- ubuntu_linuxEOL14.04 | 16.04 | 18.04 | 18.10
Debian1 product
- busybox< 1:1.30.1-1
Ubuntu1 product
- busybox< 1:1.21.0-1ubuntu1.4 | < 1:1.22.0-15ubuntu1.4 | < 1:1.27.2-2ubuntu3.2
5 vendors · 5 products
References
12 links- git.busybox.net/busybox/commit/?id=6d3b4bb24da9a07c263f3c1acf8df85382ff562cX Refsource MISCPatchThird Party Advisory
