Vulnerability Name:

CVE-2019-19331 (CCN-172538)

Assigned:2019-12-04
Published:2019-12-04
Updated:2019-12-17
Summary:knot-resolver before version 4.3.0 is vulnerable to denial of service through high CPU utilization. DNS replies with very many resource records might be processed very inefficiently, in extreme cases taking even several CPU seconds for each such uncached message. For example, a few thousand A records can be squashed into one DNS message (limit is 64kB).
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
7.5 High (CCN 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 (CCN 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
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
7.8 High (CCN CVSS v2 Vector: AV:N/AC:L/Au:N/C:N/I:N/A:C)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Low
Athentication (Au): None
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): Complete
Vulnerability Type:CWE-404
Vulnerability Consequences:Denial of Service
References:Source: MITRE
Type: CNA
CVE-2019-19331

Source: CONFIRM
Type: Exploit, Issue Tracking, Patch
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-19331

Source: XF
Type: UNKNOWN
knot-cve201919331-dos(172538)

Source: CCN
Type: oss-sec Mailing List, Wed, 4 Dec 2019 17:48:33 +0100
[CVE-2019-19331] Knot Resolver 4.3.0 security release

Source: CCN
Type: Knot Web site
Knot Resolver

Source: MISC
Type: Release Notes, Vendor Advisory
https://www.knot-resolver.cz/2019-12-04-knot-resolver-4.3.0.html

Vulnerable Configuration:Configuration 1:
  • cpe:/a:nic:knot_resolver:*:*:*:*:*:*:*:* (Version < 4.3.0)

    • Configuration 2:
  • cpe:/o:debian:debian_linux:10.0:*:*:*:*:*:*:*

    • Configuration CCN 1:
  • cpe:/a:nic:knot_resolver:4.2.2:*:*:*:*:*:*:*

    • * Denotes that component is vulnerable
    Oval Definitions
    Definition IDClassTitleLast Modified
    oval:com.ubuntu.disco:def:2019193310000000
    V
    		CVE-2019-19331 on Ubuntu 19.04 (disco) - medium.
    2019-12-16
    oval:com.ubuntu.bionic:def:2019193310000000
    V
    		CVE-2019-19331 on Ubuntu 18.04 LTS (bionic) - medium.
    2019-12-16
    oval:com.ubuntu.xenial:def:2019193310000000
    V
    		CVE-2019-19331 on Ubuntu 16.04 LTS (xenial) - medium.
    2019-12-16
    BACK
    nic knot resolver *
    debian debian linux 10.0
    nic knot resolver 4.2.2