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This script is Copyright (C) 2023 and is owned by Tenable, Inc. or an Affiliate thereof.ORACLELINUX_ELSA-2023-12972.NASL
HistoryNov 06, 2023 - 12:00 a.m.

Oracle Linux 7 : dnsmasq (ELSA-2023-12972)

2023-11-0600:00:00
This script is Copyright (C) 2023 and is owned by Tenable, Inc. or an Affiliate thereof.
www.tenable.com

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AI Score

Confidence

High

The remote Oracle Linux 7 host has packages installed that are affected by multiple vulnerabilities as referenced in the ELSA-2023-12972 advisory.

  • A flaw was found in dnsmasq before version 2.83. A heap-based buffer overflow was discovered in the way RRSets are sorted before validating with DNSSEC data. An attacker on the network, who can forge DNS replies such as that they are accepted as valid, could use this flaw to cause a buffer overflow with arbitrary data in a heap memory segment, possibly executing code on the machine. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.
    (CVE-2020-25681)

  • A flaw was found in dnsmasq before 2.83. A buffer overflow vulnerability was discovered in the way dnsmasq extract names from DNS packets before validating them with DNSSEC data. An attacker on the network, who can create valid DNS replies, could use this flaw to cause an overflow with arbitrary data in a heap- allocated memory, possibly executing code on the machine. The flaw is in the rfc1035.c:extract_name() function, which writes data to the memory pointed by name assuming MAXDNAME*2 bytes are available in the buffer. However, in some code execution paths, it is possible extract_name() gets passed an offset from the base buffer, thus reducing, in practice, the number of available bytes that can be written in the buffer. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability. (CVE-2020-25682)

Note that Nessus has not tested for these issues but has instead relied only on the applicationโ€™s self-reported version number.

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Oracle Linux Security Advisory ELSA-2023-12972.
##

include('compat.inc');

if (description)
{
  script_id(184789);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/11/07");

  script_cve_id("CVE-2020-25681", "CVE-2020-25682");
  script_xref(name:"IAVA", value:"2021-A-0041");
  script_xref(name:"CEA-ID", value:"CEA-2021-0003");

  script_name(english:"Oracle Linux 7 : dnsmasq (ELSA-2023-12972)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Oracle Linux host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The remote Oracle Linux 7 host has packages installed that are affected by multiple vulnerabilities as referenced in the
ELSA-2023-12972 advisory.

  - A flaw was found in dnsmasq before version 2.83. A heap-based buffer overflow was discovered in the way
    RRSets are sorted before validating with DNSSEC data. An attacker on the network, who can forge DNS
    replies such as that they are accepted as valid, could use this flaw to cause a buffer overflow with
    arbitrary data in a heap memory segment, possibly executing code on the machine. The highest threat from
    this vulnerability is to data confidentiality and integrity as well as system availability.
    (CVE-2020-25681)

  - A flaw was found in dnsmasq before 2.83. A buffer overflow vulnerability was discovered in the way dnsmasq
    extract names from DNS packets before validating them with DNSSEC data. An attacker on the network, who
    can create valid DNS replies, could use this flaw to cause an overflow with arbitrary data in a heap-
    allocated memory, possibly executing code on the machine. The flaw is in the rfc1035.c:extract_name()
    function, which writes data to the memory pointed by name assuming MAXDNAME*2 bytes are available in the
    buffer. However, in some code execution paths, it is possible extract_name() gets passed an offset from
    the base buffer, thus reducing, in practice, the number of available bytes that can be written in the
    buffer. The highest threat from this vulnerability is to data confidentiality and integrity as well as
    system availability. (CVE-2020-25682)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version
number.");
  script_set_attribute(attribute:"see_also", value:"https://linux.oracle.com/errata/ELSA-2023-12972.html");
  script_set_attribute(attribute:"solution", value:
"Update the affected dnsmasq and / or dnsmasq-utils packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:P/I:P/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/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-2020-25682");

  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:"2021/01/19");
  script_set_attribute(attribute:"patch_publication_date", value:"2023/11/06");
  script_set_attribute(attribute:"plugin_publication_date", value:"2023/11/06");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:oracle:linux:7:9:patch");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:oracle:linux:7::latest");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:oracle:linux:7::optional_latest");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:oracle:linux:7");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:dnsmasq");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:dnsmasq-utils");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_set_attribute(attribute:"stig_severity", value:"I");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Oracle Linux Local Security Checks");

  script_copyright(english:"This script is Copyright (C) 2023 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/OracleLinux", "Host/RedHat/release", "Host/RedHat/rpm-list", "Host/local_checks_enabled");

  exit(0);
}


include('rpm.inc');

if (!get_kb_item('Host/local_checks_enabled')) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (!get_kb_item('Host/OracleLinux')) audit(AUDIT_OS_NOT, 'Oracle Linux');
var os_release = get_kb_item("Host/RedHat/release");
if (isnull(os_release) || !pregmatch(pattern: "Oracle (?:Linux Server|Enterprise Linux)", string:os_release)) audit(AUDIT_OS_NOT, 'Oracle Linux');
var os_ver = pregmatch(pattern: "Oracle (?:Linux Server|Enterprise Linux) .*release ([0-9]+(\.[0-9]+)?)", string:os_release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, 'Oracle Linux');
os_ver = os_ver[1];
if (! preg(pattern:"^7([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, 'Oracle Linux 7', 'Oracle Linux ' + 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$" && 'aarch64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Oracle Linux', cpu);

var pkgs = [
    {'reference':'dnsmasq-2.76-17.0.3.el7_9.3', 'cpu':'aarch64', 'release':'7', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'dnsmasq-utils-2.76-17.0.3.el7_9.3', 'cpu':'aarch64', 'release':'7', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'dnsmasq-2.76-17.0.3.el7_9.3', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'dnsmasq-utils-2.76-17.0.3.el7_9.3', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE}
];

var flag = 0;
foreach var 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;
  var exists_check = NULL;
  if (!empty_or_null(package_array['reference'])) reference = package_array['reference'];
  if (!empty_or_null(package_array['release'])) _release = 'EL' + 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 (!empty_or_null(package_array['exists_check'])) exists_check = package_array['exists_check'];
  if (reference && _release) {
    if (exists_check) {
        if (rpm_exists(release:_release, rpm:exists_check) && 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++;
    } else {
        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_HOLE,
      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, 'dnsmasq / dnsmasq-utils');
}
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AI Score

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