EulerOS 2.0 SP13 : dnsmasq (EulerOS-SA-2026-2963)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
##

include('compat.inc');

if (description)
{
  script_id(332788);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/08/06");

  script_cve_id(
    "CVE-2026-2291",
    "CVE-2026-4890",
    "CVE-2026-4891",
    "CVE-2026-4892",
    "CVE-2026-4893"
  );
  script_xref(name:"IAVA", value:"2026-A-0450");

  script_name(english:"EulerOS 2.0 SP13 : dnsmasq (EulerOS-SA-2026-2963)");

  script_set_attribute(attribute:"synopsis", value:
"The remote EulerOS host is missing multiple security updates.");
  script_set_attribute(attribute:"description", value:
"According to the versions of the dnsmasq packages installed, the EulerOS installation on the remote host is affected by
the following vulnerabilities :

    A Denial of Service (DoS) vulnerability in the DNSSEC validation of dnsmasq allows remote attackers to
    cause a denial of service via a crafted DNS packet.(CVE-2026-4890)

    A heap-based out-of-bounds write vulnerability in the DHCPv6 implementation of dnsmasq allows local
    attackers to execute arbitrary code with root privileges via a crafted DHCPv6 packet.(CVE-2026-4892)

    A heap-based out-of-bounds read vulnerability in the DNSSEC validation of dnsmasq allows remote attackers
    to cause a denial of service via a crafted DNS packet.(CVE-2026-4891)

    An information disclosure vulnerability in dnsmasq allows remote attackers to bypass source checks via a
    crafted DNS packet with RFC 7871 client subnet information.(CVE-2026-4893)

    dnsmasqs extract_name() function can be abused to cause a heap buffer overflow, allowing an attacker to
    inject false DNS cache entries, which could result in DNS lookups to redirect to an attacker-controlled IP
    address, or to cause a DoS.(CVE-2026-2291)

Tenable has extracted the preceding description block directly from the EulerOS dnsmasq security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version
number.");
  # https://developer.huaweicloud.com/ict/en/site-euleros/euleros/security-advisories/EulerOS-SA-2026-2963
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?d9e40fde");
  script_set_attribute(attribute:"solution", value:
"Update the affected dnsmasq packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-2291");
  script_set_attribute(attribute:"cvss3_score_source", value:"CVE-2026-4892");

  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:"2026/05/11");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/08/06");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/08/06");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:dnsmasq");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:dnsmasq-help");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:huawei:euleros:2.0");
  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:"Huawei Local Security Checks");

  script_copyright(english:"This script is Copyright (C) 2026 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/cpu", "Host/EulerOS/release", "Host/EulerOS/rpm-list", "Host/EulerOS/sp");
  script_exclude_keys("Host/EulerOS/uvp_version");

  exit(0);
}

include("rpm.inc");

if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);

var _release = get_kb_item("Host/EulerOS/release");
if (isnull(_release) || _release !~ "^EulerOS") audit(AUDIT_OS_NOT, "EulerOS");
var uvp = get_kb_item("Host/EulerOS/uvp_version");
if (_release !~ "^EulerOS release 2\.0(\D|$)") audit(AUDIT_OS_NOT, "EulerOS 2.0 SP13");

var sp = get_kb_item("Host/EulerOS/sp");
if (isnull(sp) || sp !~ "^(13)$") audit(AUDIT_OS_NOT, "EulerOS 2.0 SP13");

if (!empty_or_null(uvp)) audit(AUDIT_OS_NOT, "EulerOS 2.0 SP13", "EulerOS UVP " + uvp);

if (!get_kb_item("Host/EulerOS/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$" && "aarch64" >!< cpu && "x86" >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "EulerOS", cpu);
if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$" && "x86" >!< cpu) audit(AUDIT_ARCH_NOT, "i686 / x86_64", cpu);

var flag = 0;

var pkgs = [
  "dnsmasq-2.86-7.h13.eulerosv2r13",
  "dnsmasq-help-2.86-7.h13.eulerosv2r13"
];

foreach (var pkg in pkgs)
  if (rpm_check(release:"EulerOS-2.0", sp:"13", reference:pkg)) 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");
}