Vulnerability in Nlnet Labs Unbound

CVE-2022-30698

NLnet Labs Unbound, up to and including version 1.16.1 is vulnerable to a novel type of the "ghost domain names" attack. The vulnerability works by targeting an Unbound instance. Unbound is queried for a subdomain of a rogue domain name. The rogue nameserver returns delegation information for the subdomain that updates Unbound's delegation cache. This action can be repeated before expiry of the delegation information by querying Unbound for a second level subdomain which the rogue nameserver provides new delegation information. Since Unbound is a child-centric resolver, the ever-updating child delegation information can keep a rogue domain name resolvable long after revocation. From version 1.16.2 on, Unbound checks the validity of parent delegation records before using cached delegation information.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.011 (64.9th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 65th percentile — 64.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2022-30698: held from 0.011 to 0.011.

EPSS over last 30 days · oldest: 0.011 · newest: 0.011 · change: +0.001

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2022-30698?
CVE-2022-30698 is a medium-severity vulnerability in Nlnet Labs Unbound, classified under Insufficient Session Expiration. CVSS score: 6.5/10. Published 2022-08-01.
How severe is CVE-2022-30698?
Medium severity. CVSS v3 base score is 6.5 out of 10.
Is CVE-2022-30698 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.