#VU10427 Spoofing attack in OpenBSD

Vulnerability identifier: #VU10427

Vulnerability risk: Low

CVSSv4.0: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]

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

---

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

---

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.