CVE-2017-15105

Severity: medium (CVSS 5.3 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 3.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2018-01-23 · updated 2026-06-17
Weakness: CWE-358

Description

A flaw was found in the way unbound before 1.6.8 validated wildcard-synthesized NSEC records. An improperly validated wildcard NSEC record could be used to prove the non-existence (NXDOMAIN answer) of an existing wildcard record, or trick unbound into accepting a NODATA proof.

Affected products

Canonical Ubuntu Linux: 14.04, 16.04, 17.10, 18.04
Debian Linux: 7.0, 8.0
NLnet Labs Unbound: before 1.6.8 — fixed in 1.6.8

How to fix

Upgrade to a fixed version: NLnet Labs Unbound 1.6.8. Check the vendor advisory for mitigations.

References

http://www.securityfocus.com/bid/102817
https://lists.debian.org/debian-lts-announce/2018/01/msg00039.html
https://lists.debian.org/debian-lts-announce/2019/02/msg00022.html
https://unbound.net/downloads/CVE-2017-15105.txt
https://usn.ubuntu.com/3673-1/
http://www.securityfocus.com/bid/102817
https://lists.debian.org/debian-lts-announce/2018/01/msg00039.html
https://lists.debian.org/debian-lts-announce/2019/02/msg00022.html
https://unbound.net/downloads/CVE-2017-15105.txt
https://usn.ubuntu.com/3673-1/

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