CVE-2022-30698

Publication date 1 August 2022

Last updated 24 July 2024

Ubuntu priority

Cvss 3 Severity Score

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.

Status

Show unmaintained releases

Package	Ubuntu Release	Status
unbound	24.04 LTS noble	Fixed 1.16.2-1
	23.10 mantic	Fixed 1.16.2-1
	23.04 lunar	Fixed 1.16.2-1
	22.10 kinetic	Fixed 1.16.2-1
	22.04 LTS jammy	Fixed 1.13.1-1ubuntu5.1
	20.04 LTS focal	Fixed 1.9.4-2ubuntu1.3
	18.04 LTS bionic	Fixed 1.6.7-1ubuntu2.5
	16.04 LTS xenial	Vulnerable
	14.04 LTS trusty	Vulnerable

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
unbound	Upstream: f6753a0

Severity score breakdown

Parameter	Value
Base score	6.5 · Medium
Attack vector	Network
Attack complexity	Low
Privileges required	Low
User interaction	None
Scope	Unchanged
Confidentiality	High
Integrity impact	None
Availability impact	None
Vector	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

References

Related Ubuntu Security Notices (USN)

USN-5569-1
Unbound vulnerabilities
16 August 2022