Resource exhaustion in Nic Knot Resolver
CVE-2020-12667
Knot Resolver before 5.1.1 allows traffic amplification via a crafted DNS answer from an attacker-controlled server, aka an "NXNSAttack" issue. This is triggered by random subdomains in the NSDNAME in NS records.
Vulnerability class: DoS (Denial of Service)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.025 (84.4th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 84th percentile — 84.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.026 · newest: 0.025 · change: -0.001
Affected products
Weakness classification (CWE)
References
- en.blog.nic.cz/2020/05/19/nxnsattack-upgrade-resolvers-to-stop-new-kind-of-rand… (Technical Description, Vendor Advisory)
- www.knot-resolver.cz/2020-05-19-knot-resolver-5.1.1.html (Release Notes, Vendor Advisory)
- www.openwall.com/lists/oss-security/2020/05/19/2 (mailing-list, Mailing List, Third Party Advisory)
- cyber-security-group.cs.tau.ac.il/ (Technical Description, Third Party Advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- lists.debian.org/debian-lts-announce/2024/04/msg00017.html (mailing-list)
Frequently asked questions
- What is CVE-2020-12667?
- CVE-2020-12667 is a high-severity vulnerability in Nic Knot Resolver, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2020-05-19.
- How severe is CVE-2020-12667?
- High severity. CVSS v3 base score is 7.5 out of 10.