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Vulnerability · Published Aug 1, 2022 · Assigned by NLnet Labs

CVE-2022-30699Novel "ghost domain names" attack by updating almost expired delegation information

Medium 6.5

In plain English

A medium-severity security flaw in Unbound from NLnet Labs. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.2% (higher than 67% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)6.5Medium
Exploit odds (30 days)1.2%top 32.8% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known

Official description

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 rogue domain name when the cached delegation information is about to expire. The rogue nameserver delays the response so that the cached delegation information is expired. Upon receiving the delayed answer containing the delegation information, Unbound overwrites the now expired entries. This action can be repeated when the delegation information is about to expire making the rogue delegation information ever-updating. From version 1.16.2 on, Unbound stores the start time for a query and uses that to decide if the cached delegation information can be overwritten.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
AlmaLinux:8python3-unbound1.16.2-2.el8ALSA-2022:7622
AlmaLinux:9python3-unbound1.16.2-2.el9ALSA-2022:8062
AlmaLinux:8unbound1.16.2-2.el8ALSA-2022:7622
AlmaLinux:9unbound1.16.2-2.el9ALSA-2022:8062
AlmaLinux:8unbound-devel1.16.2-2.el8ALSA-2022:7622
AlmaLinux:9unbound-devel1.16.2-2.el9ALSA-2022:8062
AlmaLinux:8unbound-libs1.16.2-2.el8ALSA-2022:7622
AlmaLinux:9unbound-libs1.16.2-2.el9ALSA-2022:8062
Alpine:v3.20unbound1.16.2-r0ALPINE-CVE-2022-30699
Alpine:v3.21unbound1.16.2-r0ALPINE-CVE-2022-30699
Alpine:v3.22unbound1.16.2-r0ALPINE-CVE-2022-30699
Alpine:v3.23unbound1.16.2-r0ALPINE-CVE-2022-30699
Alpine:v3.24unbound1.16.2-r0ALPINE-CVE-2022-30699
Debian:12unbound1.16.2-1DEBIAN-CVE-2022-30699
Debian:13unbound1.16.2-1DEBIAN-CVE-2022-30699
Debian:14unbound1.16.2-1DEBIAN-CVE-2022-30699
Rocky Linux:8unbound0:1.16.2-2.el8RLSA-2022:7622
Rocky Linux:9unbound0:1.16.2-2.el9RLSA-2022:8062
Ubuntu:22.04:LTSunbound1.13.1-1ubuntu5.1UBUNTU-CVE-2022-30699
Ubuntu:22.04:LTSunbound1.13.1-1ubuntu5.1USN-5569-1

Affected products (as reported)

VendorProductVersions
NLnet Labs Unbound unspecified – through 1.16.1

References