#VU69407 Resource exhaustion in Unbound - CVE-2022-3204

Vulnerability identifier: #VU69407

Vulnerability risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2022-3204

CWE-ID: CWE-400

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Unbound
Server applications / DNS servers

Vendor: NLnet Labs

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to application does not properly control consumption of internal resources when processing a malicious delegation with a considerable number of non responsive nameservers. A remote attacker can trigger CPU high usage and perform a denial of service (DoS) attack.

The attack is known as "Non-Responsive Delegation Attack" (NRDelegation Attack).

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Unbound: 1.0.0 - 1.16.2

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External links
https://www.nlnetlabs.nl/downloads/unbound/CVE-2022-3204.txt

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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.