CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:N/I:N/A:P
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
AI Score
Confidence
Low
EPSS
Percentile
85.2%
The remote Debian 10 host has packages installed that are affected by multiple vulnerabilities as referenced in the dla-3795 advisory.
A vulnerability was discovered in DNS resolver component of knot resolver through version 3.2.0 before 4.1.0 which allows remote attackers to bypass DNSSEC validation for non-existence answer. NXDOMAIN answer would get passed through to the client even if its DNSSEC validation failed, instead of sending a SERVFAIL packet. Caching is not affected by this particular bug but see CVE-2019-10191. (CVE-2019-10190)
A vulnerability was discovered in DNS resolver of knot resolver before version 4.1.0 which allows remote attackers to downgrade DNSSEC-secure domains to DNSSEC-insecure state, opening possibility of domain hijack using attacks against insecure DNS protocol. (CVE-2019-10191)
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). (CVE-2019-19331)
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. (CVE-2020-12667)
Note that Nessus has not tested for these issues but has instead relied only on the application’s self-reported version number.
#%NASL_MIN_LEVEL 80900
#
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Debian Security Advisory dla-3795. The text
# itself is copyright (C) Software in the Public Interest, Inc.
#
include('compat.inc');
if (description)
{
script_id(193916);
script_version("1.0");
script_set_attribute(attribute:"plugin_modification_date", value:"2024/04/26");
script_cve_id(
"CVE-2019-10190",
"CVE-2019-10191",
"CVE-2019-19331",
"CVE-2020-12667"
);
script_name(english:"Debian dla-3795 : knot-resolver - security update");
script_set_attribute(attribute:"synopsis", value:
"The remote Debian host is missing one or more security-related updates.");
script_set_attribute(attribute:"description", value:
"The remote Debian 10 host has packages installed that are affected by multiple vulnerabilities as referenced in the
dla-3795 advisory.
- A vulnerability was discovered in DNS resolver component of knot resolver through version 3.2.0 before
4.1.0 which allows remote attackers to bypass DNSSEC validation for non-existence answer. NXDOMAIN answer
would get passed through to the client even if its DNSSEC validation failed, instead of sending a SERVFAIL
packet. Caching is not affected by this particular bug but see CVE-2019-10191. (CVE-2019-10190)
- A vulnerability was discovered in DNS resolver of knot resolver before version 4.1.0 which allows remote
attackers to downgrade DNSSEC-secure domains to DNSSEC-insecure state, opening possibility of domain
hijack using attacks against insecure DNS protocol. (CVE-2019-10191)
- 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). (CVE-2019-19331)
- 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. (CVE-2020-12667)
Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version
number.");
# https://security-tracker.debian.org/tracker/source-package/knot-resolver
script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?8a867234");
script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2019-10190");
script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2019-10191");
script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2019-19331");
script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2020-12667");
script_set_attribute(attribute:"see_also", value:"https://packages.debian.org/source/buster/knot-resolver");
script_set_attribute(attribute:"solution", value:
"Upgrade the knot-resolver packages.");
script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:P/A:N");
script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N");
script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
script_set_attribute(attribute:"cvss_score_source", value:"CVE-2019-10191");
script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
script_set_attribute(attribute:"exploit_available", value:"true");
script_set_attribute(attribute:"vuln_publication_date", value:"2019/07/10");
script_set_attribute(attribute:"patch_publication_date", value:"2024/04/26");
script_set_attribute(attribute:"plugin_publication_date", value:"2024/04/26");
script_set_attribute(attribute:"plugin_type", value:"local");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:knot-resolver");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:knot-resolver-doc");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:knot-resolver-module-http");
script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:10.0");
script_set_attribute(attribute:"generated_plugin", value:"current");
script_end_attributes();
script_category(ACT_GATHER_INFO);
script_family(english:"Debian Local Security Checks");
script_copyright(english:"This script is Copyright (C) 2024 and is owned by Tenable, Inc. or an Affiliate thereof.");
script_dependencies("ssh_get_info.nasl");
script_require_keys("Host/local_checks_enabled", "Host/Debian/release", "Host/Debian/dpkg-l");
exit(0);
}
include('debian_package.inc');
if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (!get_kb_item("Host/Debian/dpkg-l")) audit(AUDIT_PACKAGE_LIST_MISSING);
var debian_release = get_kb_item('Host/Debian/release');
if ( isnull(debian_release) ) audit(AUDIT_OS_NOT, 'Debian');
debian_release = chomp(debian_release);
if (! preg(pattern:"^(10)\.[0-9]+", string:debian_release)) audit(AUDIT_OS_NOT, 'Debian 10.0', 'Debian ' + debian_release);
var cpu = get_kb_item('Host/cpu');
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ('x86_64' >!< cpu && cpu !~ "^i[3-6]86$" && 'aarch64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Debian', cpu);
var pkgs = [
{'release': '10.0', 'prefix': 'knot-resolver', 'reference': '3.2.1-3+deb10u2'},
{'release': '10.0', 'prefix': 'knot-resolver-doc', 'reference': '3.2.1-3+deb10u2'},
{'release': '10.0', 'prefix': 'knot-resolver-module-http', 'reference': '3.2.1-3+deb10u2'}
];
var flag = 0;
foreach package_array ( pkgs ) {
var _release = NULL;
var prefix = NULL;
var reference = NULL;
if (!empty_or_null(package_array['release'])) _release = package_array['release'];
if (!empty_or_null(package_array['prefix'])) prefix = package_array['prefix'];
if (!empty_or_null(package_array['reference'])) reference = package_array['reference'];
if (_release && prefix && reference) {
if (deb_check(release:_release, prefix:prefix, reference:reference)) flag++;
}
}
if (flag)
{
security_report_v4(
port : 0,
severity : SECURITY_WARNING,
extra : deb_report_get()
);
exit(0);
}
else
{
var tested = deb_pkg_tests_get();
if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'knot-resolver / knot-resolver-doc / knot-resolver-module-http');
}
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-10190
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-10191
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-19331
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-12667
www.nessus.org/u?8a867234
packages.debian.org/source/buster/knot-resolver
security-tracker.debian.org/tracker/CVE-2019-10190
security-tracker.debian.org/tracker/CVE-2019-10191
security-tracker.debian.org/tracker/CVE-2019-19331
security-tracker.debian.org/tracker/CVE-2020-12667
CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:N/I:N/A:P
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
AI Score
Confidence
Low
EPSS
Percentile
85.2%