Vulnerability identifier: #VU28163

Vulnerability risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-12663

CWE-ID: CWE-835

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 infinite loop when parsing DNS responses. A remote attacker can send a specially crafted DNS response to the server, consume all available system resources and cause denial of service conditions.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Unbound: 0.0 - 1.10.0 rc2

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External links
http://www.openwall.com/lists/oss-security/2020/05/19/5
http://nlnetlabs.nl/downloads/unbound/CVE-2020-12662_2020-12663.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.