Ubuntu update for knot-resolver

1) Resource exhaustion

EUVDB-ID: #VU78292

Risk: Medium

CVSSv4.0: 4.6 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2022-40188

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 caused by algorithmic complexity. A malicious authoritative server can return large NS sets or addresses and cause excessive CPU consumption. 

Mitigation

Update the affected package knot-resolver to the latest version.

Vulnerable software versions

Ubuntu: 16.04 - 22.10

libkres-dev (Ubuntu package): before Ubuntu Pro

libkres6 (Ubuntu package): before Ubuntu Pro

knot-resolver (Ubuntu package): before 3.2.1-3ubuntu2.1

CPE2.3

• cpe:2.3:o:canonical:ubuntu:16.04:*:*:*:*:*:*:*
• 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:a:canonical:libkres-dev_ubuntu_package:*:*:*:*:*:ubuntu:*:*
• cpe:2.3:a:canonical:libkres6_ubuntu_package:*:*:*:*:*:ubuntu:*:*
• cpe:2.3:a:canonical:knot-resolver_ubuntu_package:*:*:*:*:*:ubuntu:*:*

External links

https://ubuntu.com/security/notices/USN-6225-1

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.