Vulnerability identifier: #VU45005

Vulnerability risk: Medium

CVSSv3.1: 4.6 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:U/RL:O/RC:C]

CVE-ID: CVE-2009-4008

CWE-ID: CWE-399

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Unbound
Server applications / DNS servers

Vendor: NLnet Labs

Description

The vulnerability allows a remote non-authenticated attacker to perform service disruption.

Unbound before 1.4.4 does not send responses for signed zones after mishandling an unspecified query, which allows remote attackers to cause a denial of service (DNSSEC outage) via a crafted query.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Unbound: 0.0 - 1.4.2

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External links
http://packages.debian.org/changelogs/pool/main/u/unbound/unbound_1.4.6-1/changelog
http://unbound.nlnetlabs.nl/downloads/unbound-1.4.4.tar.gz
http://www.debian.org/security/2011/dsa-2243

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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.