#VU29248 Resource exhaustion in Knot Resolver - CVE-2020-12667
Published: June 25, 2020
Vulnerability identifier: #VU29248
Vulnerability risk: Medium
CVSSv4.0: 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:U/U:Green
CVE-ID: CVE-2020-12667
CWE-ID: CWE-400
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerable software:
Knot Resolver
Knot Resolver
Software vendor:
Nic
Nic
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 when processing NSDNAME in NS records. A remote attacker can perform traffic amplification via a crafted DNS answer from an attacker-controlled server. This vulnerability is dubbed "NXNSAttack".
Remediation
Install updates from vendor's website.
External links
- http://cyber-security-group.cs.tau.ac.il/#
- http://www.openwall.com/lists/oss-security/2020/05/19/2
- https://en.blog.nic.cz/2020/05/19/nxnsattack-upgrade-resolvers-to-stop-new-kind-of-random-subdomain-attack/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/76Y4FITMOH6RVPWAANGV7NB2ZHPJJGDQ/
- https://www.knot-resolver.cz/2020-05-19-knot-resolver-5.1.1.html