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nessusThis script is Copyright (C) 2024 and is owned by Tenable, Inc. or an Affiliate thereof.FEDORA_2024-5BFA220621.NASL
HistoryApr 28, 2024 - 12:00 a.m.

Fedora 38 : unbound (2024-5bfa220621)

2024-04-2800:00:00
This script is Copyright (C) 2024 and is owned by Tenable, Inc. or an Affiliate thereof.
www.tenable.com
1
fedora 38
denial of service
vulnerability
nlnet labs unbound
cve-2024-1931
nessus scanner

7.5 High

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

6.7 Medium

AI Score

Confidence

High

0.0004 Low

EPSS

Percentile

15.5%

The remote Fedora 38 host has a package installed that is affected by a vulnerability as referenced in the FEDORA-2024-5bfa220621 advisory.

  • NLnet Labs Unbound version 1.18.0 up to and including version 1.19.1 contain a vulnerability that can cause denial of service by a certain code path that can lead to an infinite loop. Unbound 1.18.0 introduced a feature that removes EDE records from responses with size higher than the client’s advertised buffer size. Before removing all the EDE records however, it would try to see if trimming the extra text fields on those records would result in an acceptable size while still retaining the EDE codes. Due to an unchecked condition, the code that trims the text of the EDE records could loop indefinitely. This happens when Unbound would reply with attached EDE information on a positive reply and the client’s buffer size is smaller than the needed space to include EDE records. The vulnerability can only be triggered when the ‘ede: yes’ option is used; non default configuration. From version 1.19.2 on, the code is fixed to avoid looping indefinitely. (CVE-2024-1931)

Note that Nessus has not tested for this issue 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 Fedora Security Advisory FEDORA-2024-5bfa220621
#

include('compat.inc');

if (description)
{
  script_id(194343);
  script_version("1.0");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/04/28");

  script_cve_id("CVE-2024-1931");
  script_xref(name:"FEDORA", value:"2024-5bfa220621");

  script_name(english:"Fedora 38 : unbound (2024-5bfa220621)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Fedora host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The remote Fedora 38 host has a package installed that is affected by a vulnerability as referenced in the
FEDORA-2024-5bfa220621 advisory.

  - NLnet Labs Unbound version 1.18.0 up to and including version 1.19.1 contain a vulnerability that can
    cause denial of service by a certain code path that can lead to an infinite loop. Unbound 1.18.0
    introduced a feature that removes EDE records from responses with size higher than the client's advertised
    buffer size. Before removing all the EDE records however, it would try to see if trimming the extra text
    fields on those records would result in an acceptable size while still retaining the EDE codes. Due to an
    unchecked condition, the code that trims the text of the EDE records could loop indefinitely. This happens
    when Unbound would reply with attached EDE information on a positive reply and the client's buffer size is
    smaller than the needed space to include EDE records. The vulnerability can only be triggered when the
    'ede: yes' option is used; non default configuration. From version 1.19.2 on, the code is fixed to avoid
    looping indefinitely. (CVE-2024-1931)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version
number.");
  script_set_attribute(attribute:"see_also", value:"https://bodhi.fedoraproject.org/updates/FEDORA-2024-5bfa220621");
  script_set_attribute(attribute:"solution", value:
"Update the affected unbound package.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:U/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:N/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2024-1931");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");

  script_set_attribute(attribute:"vuln_publication_date", value:"2024/03/07");
  script_set_attribute(attribute:"patch_publication_date", value:"2024/04/12");
  script_set_attribute(attribute:"plugin_publication_date", value:"2024/04/28");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:fedoraproject:fedora:38");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:fedoraproject:fedora:unbound");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Fedora 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/RedHat/release", "Host/RedHat/rpm-list");

  exit(0);
}


include('rpm.inc');

if (!get_kb_item('Host/local_checks_enabled')) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
var os_release = get_kb_item('Host/RedHat/release');
if (isnull(os_release) || 'Fedora' >!< os_release) audit(AUDIT_OS_NOT, 'Fedora');
var os_ver = pregmatch(pattern: "Fedora.*release ([0-9]+)", string:os_release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, 'Fedora');
os_ver = os_ver[1];
if (! preg(pattern:"^38([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, 'Fedora 38', 'Fedora ' + os_ver);

if (!get_kb_item('Host/RedHat/rpm-list')) audit(AUDIT_PACKAGE_LIST_MISSING);

var cpu = get_kb_item('Host/cpu');
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ('x86_64' >!< cpu && cpu !~ "^i[3-6]86$" && 's390' >!< cpu && 'aarch64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Fedora', cpu);

var pkgs = [
    {'reference':'unbound-1.19.3-1.fc38', 'release':'FC38', 'rpm_spec_vers_cmp':TRUE}
];

var flag = 0;
foreach package_array ( pkgs ) {
  var reference = NULL;
  var _release = NULL;
  var sp = NULL;
  var _cpu = NULL;
  var el_string = NULL;
  var rpm_spec_vers_cmp = NULL;
  var epoch = NULL;
  var allowmaj = NULL;
  if (!empty_or_null(package_array['reference'])) reference = package_array['reference'];
  if (!empty_or_null(package_array['release'])) _release = package_array['release'];
  if (!empty_or_null(package_array['sp'])) sp = package_array['sp'];
  if (!empty_or_null(package_array['cpu'])) _cpu = package_array['cpu'];
  if (!empty_or_null(package_array['el_string'])) el_string = package_array['el_string'];
  if (!empty_or_null(package_array['rpm_spec_vers_cmp'])) rpm_spec_vers_cmp = package_array['rpm_spec_vers_cmp'];
  if (!empty_or_null(package_array['epoch'])) epoch = package_array['epoch'];
  if (!empty_or_null(package_array['allowmaj'])) allowmaj = package_array['allowmaj'];
  if (reference && _release) {
    if (rpm_check(release:_release, sp:sp, cpu:_cpu, reference:reference, epoch:epoch, el_string:el_string, rpm_spec_vers_cmp:rpm_spec_vers_cmp, allowmaj:allowmaj)) flag++;
  }
}

if (flag)
{
  security_report_v4(
      port       : 0,
      severity   : SECURITY_WARNING,
      extra      : rpm_report_get()
  );
  exit(0);
}
else
{
  var tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'unbound');
}
VendorProductVersionCPE
fedoraprojectfedora38cpe:/o:fedoraproject:fedora:38
fedoraprojectfedoraunboundp-cpe:/a:fedoraproject:fedora:unbound

7.5 High

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

6.7 Medium

AI Score

Confidence

High

0.0004 Low

EPSS

Percentile

15.5%