Vulnerability Name:

CVE-2020-12667 (CCN-182175)

Assigned:2020-05-19
Published:2020-05-19
Updated:2020-05-28
Summary: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.
CVSS v3 Severity:7.5 High (CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
6.5 Medium (Temporal CVSS v3.1 Vector: 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)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): High
5.3 Medium (CCN CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L)
4.6 Medium (CCN Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): Low
CVSS v2 Severity:5.0 Medium (CVSS v2 Vector: AV:N/AC:L/Au:N/C:N/I:N/A:P)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Low
Authentication (Au): None
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): Partial
5.0 Medium (CCN CVSS v2 Vector: AV:N/AC:L/Au:N/C:N/I:N/A:P)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Low
Athentication (Au): None
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): Partial
Vulnerability Type:CWE-400
Vulnerability Consequences:Denial of Service
References:Source: MITRE
Type: CNA
CVE-2020-12667

Source: MISC
Type: Technical Description, Third Party Advisory
http://cyber-security-group.cs.tau.ac.il/#

Source: MLIST
Type: Mailing List, Third Party Advisory
[oss-security] 20200519 [CVE-2020-12667] Knot Resolver 5.1.1 NXNSAttack mitigation

Source: MISC
Type: Technical Description, Vendor Advisory
https://en.blog.nic.cz/2020/05/19/nxnsattack-upgrade-resolvers-to-stop-new-kind-of-random-subdomain-attack/

Source: XF
Type: UNKNOWN
knotresolver-cve202012667-dos(182175)

Source: FEDORA
Type: UNKNOWN
FEDORA-2020-bf68101ad3

Source: CCN
Type: oss-sec Mailing List, Tue, 19 May 2020 12:40:00 +0200
[CVE-2020-12667] Knot Resolver 5.1.1 NXNSAttack mitigation

Source: CCN
Type: Knot Resolver Web site
Knot Resolver

Source: CONFIRM
Type: Release Notes, Vendor Advisory
https://www.knot-resolver.cz/2020-05-19-knot-resolver-5.1.1.html

Source: CCN
Type: WhiteSource Vulnerability Database
CVE-2020-12667

Vulnerable Configuration:Configuration 1:
  • cpe:/a:nic:knot_resolver:*:*:*:*:*:*:*:* (Version < 5.1.1)

  • * Denotes that component is vulnerable
    BACK
    nic knot resolver *