Ubuntu update for unbound

Published: 2024-02-28 | Updated: 2024-08-23

Risk	Medium
Patch available	YES
Number of vulnerabilities	2
CVE-ID	CVE-2023-50387 CVE-2023-50868
CWE-ID	CWE-400
Exploitation vector	Network
Public exploit	Public exploit code for vulnerability #1 is available. Public exploit code for vulnerability #2 is available.
Vulnerable software	Ubuntu Operating systems & Components / Operating system unbound (Ubuntu package) Operating systems & Components / Operating system package or component libunbound8 (Ubuntu package) Operating systems & Components / Operating system package or component
Vendor	Canonical Ltd.

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

1) Resource exhaustion

EUVDB-ID: #VU86377

Risk: Medium

CVSSv4.0: 7.7 [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:P/U:Green]

CVE-ID: CVE-2023-50387

CWE-ID: CWE-400 - Resource exhaustion

Exploit availability: Yes

Description

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

The vulnerability exists due to improper input validation when processing DNSSEC related records. A remote attacker can trigger resource exhaustion by forcing the DNS server to query a specially crafted DNSSEC zone and perform a denial of service (DoS) attack.

Mitigation

Update the affected package unbound to the latest version.

Vulnerable software versions

Ubuntu: 20.04 - 23.10

unbound (Ubuntu package): before 1.9.4-2ubuntu1.5

libunbound8 (Ubuntu package): before 1.9.4-2ubuntu1.5

CPE2.3

External links

https://ubuntu.com/security/notices/USN-6665-1

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. However, proof of concept for this vulnerability is available.

2) Resource exhaustion

EUVDB-ID: #VU86378