Vulnerability identifier: #VU10427

Vulnerability risk: Low

CVSSv3.1: 5.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: N/A

CWE-ID: CWE-20

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
OpenBSD
Operating systems & Components / Operating system

Vendor: OpenBSD

Description
The vulnerability allows a remote attacker to perform spoofing attack.

The weakness exists due to a flaw in the way unbound validated wildcard-synthesized NSEC records. A remote attacker can supply a specially crafted wildcard NSEC record and prove the non-existence (NXDOMAIN answer) of an existing wildcard record, or trick unbound into accepting a NODATA proof.

Mitigation
Install update from vendor's website.

Vulnerable software versions

OpenBSD: 6.2

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External links
http://www.openbsd.org/errata62.html
http://ftp.openbsd.org/pub/OpenBSD/patches/6.2/common/008_unbound.patch.sig

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.