CVE-2020-12667

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

• ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
• AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
• Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

2.62% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 84.1% of scored records. A rank, not a probability.

NVD base score

7.5 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

NVD analysis status

Modified. NVD last modified this record on 2026-06-17.

Red Hat severity

No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2020-05-19 00:00Z6 YR AGO

Last updated

2024-08-04 12:04Z2 YR AGO

Reserved

2020-05-05

Assigning CNA

mitre

Record state

PUBLISHED

Severity

High (CVSS 7.5)

CNA CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Weaknesses

• CWE-400Uncontrolled Resource ConsumptionClass

Data version

5.1

Document digest

5d42ba9450131978317662a46782d57621175ec0481421c66037b88735a01838

• en.blog.nic.czhttps://en.blog.nic.cz/2020/05/19/nxnsattack-upgrade-resolvers-to-stop-new-kind-of-random-subdomain-attack/
• www.knot-resolver.czhttps://www.knot-resolver.cz/2020-05-19-knot-resolver-5.1.1.html
• www.openwall.com[oss-security] 20200519 [CVE-2020-12667] Knot Resolver 5.1.1 NXNSAttack mitigationhttp://www.openwall.com/lists/oss-security/2020/05/19/2mailing-list
• cyber-security-group.cs.tau.ac.ilhttp://cyber-security-group.cs.tau.ac.il/#
• lists.fedoraproject.orgFEDORA-2020-bf68101ad3https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/76Y4FITMOH6RVPWAANGV7NB2ZHPJJGDQ/vendor-advisory
• lists.debian.org[debian-lts-announce] 20240426 [SECURITY] [DLA 3795-1] knot-resolver security updatehttps://lists.debian.org/debian-lts-announce/2024/04/msg00017.htmlmailing-list