Vulnerability identifier: #VU28161
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:
CWE-ID:
CWE-20
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 insufficient validation of user-supplied input when processing DNS responses. A remote attacker who controls a malicious DNS server can send a specially crafted response and perform a denial of service (DoS) attack against third-party DNS servers.
The attack is triggered by random subdomains in the NSDNAME in NS records.
Mitigation
Install updates from vendor's website.
Vulnerable software versions
Unbound: 0.0 - 1.10.0 rc2
External links
http://www.nxnsattack.com
http://www.openwall.com/lists/oss-security/2020/05/19/5
http://nlnetlabs.nl/downloads/unbound/CVE-2020-12662_2020-12663.txt
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.