Ubuntu update for unbound

1) Resource exhaustion

EUVDB-ID: #VU69407

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 - Resource exhaustion

Exploit availability: No

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

Update the affected package unbound to the latest version.

Vulnerable software versions

Ubuntu: 18.04 - 22.10

libunbound2 (Ubuntu package): before 1.6.7-1ubuntu2.6

libunbound8 (Ubuntu package): before 1.9.4-2ubuntu1.4

unbound (Ubuntu package): before 1.6.7-1ubuntu2.6

CPE2.3

• cpe:2.3:o:canonical:ubuntu:18.04:*:*:*:*:*:*:*
• cpe:2.3:o:canonical:ubuntu:20.04:*:*:*:*:*:*:*
• cpe:2.3:o:canonical:ubuntu:22.04:*:*:*:*:*:*:*
• cpe:2.3:o:canonical:ubuntu:22.10:*:*:*:*:*:*:*
• cpe:2.3:o:canonical:libunbound2_ubuntu_package:*:*:*:*:*:ubuntu:*:*
• cpe:2.3:o:canonical:libunbound8_ubuntu_package:*:*:*:*:*:ubuntu:*:*
• cpe:2.3:o:canonical:unbound_ubuntu_package:*:*:*:*:*:ubuntu:*:*

External links

https://ubuntu.com/security/notices/USN-5732-1

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.