Denial of service in Unbound

1) Infinite loop

EUVDB-ID: #VU87205

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-2024-1931

CWE-ID: CWE-835 - Loop with Unreachable Exit Condition ('Infinite Loop')

Exploit availability: No

Description

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

The vulnerability exists due to infinite loop in EDE support when trimming EDE text on
positive replies. A remote attacker can consume all available system resources and cause denial of service conditions.

Successful exploitation of the vulnerability requires enabled support for EDE (not a default option).

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Unbound: 1.18.0 rc1 - 1.19.1

CPE2.3

• cpe:2.3:a:unbound_net:unbound:1.18.0:rc1:*:*:*:*:*:*
• cpe:2.3:a:unbound_net:unbound:1.18.0:*:*:*:*:*:*:*
• cpe:2.3:a:unbound_net:unbound:1.19.0:rc1:*:*:*:*:*:*

External links

https://github.com/NLnetLabs/unbound/releases/tag/release-1.19.2

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.