Ubuntu 24.04 LTS / 26.04 LTS / Pro Realtime 24.04 LTS : Sudo vulnerability (USN-8803-1)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-8803-1. The text
# itself is copyright (C) Canonical, Inc. See
# <https://ubuntu.com/security/notices>. Ubuntu(R) is a registered
# trademark of Canonical, Inc.
##

include('compat.inc');

if (description)
{
  script_id(349266);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/09/23");

  script_cve_id("CVE-2026-82474");
  script_xref(name:"IAVA", value:"2026-A-0312");
  script_xref(name:"USN", value:"8803-1");

  script_name(english:"Ubuntu 24.04 LTS / 26.04 LTS / Pro Realtime 24.04 LTS : Sudo vulnerability (USN-8803-1)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Ubuntu host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"The remote Ubuntu 24.04 LTS / 26.04 LTS / Pro Realtime 24.04 LTS host has packages installed that are affected by a
vulnerability as referenced in the USN-8803-1 advisory.

    Guannan Wang, Zhanpeng Liu, and Guancheng Li discovered that Sudo failed to apply intercept policy checks
    when commands were executed under certain circumstances. A local attacker permitted to run specific
    commands could possibly use this issue to bypass policy enforcement and logging, executing unauthorized
    programs.

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

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://ubuntu.com/security/notices/USN-8803-1");
  script_set_attribute(attribute:"solution", value:
"Update the affected libnss-sudo, sudo and / or sudo-ldap packages.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:S/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:L/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:"cvss4_vector", value:"CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N");
  script_set_attribute(attribute:"cvss4_threat_vector", value:"CVSS:4.0/E:U");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-82474");

  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:"2026/04/09");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/09/22");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/09/23");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:24.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:26.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:Pro:-:lts");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libnss-sudo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:sudo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:sudo-ldap");
  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:"Ubuntu Local Security Checks");

  script_copyright(english:"Ubuntu Security Notice (C) 2026 Canonical, Inc. / NASL script (C) 2026 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/cpu", "Host/Ubuntu", "Host/Ubuntu/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);
var os_release = get_kb_item('Host/Ubuntu/release');
if ( isnull(os_release) ) audit(AUDIT_OS_NOT, 'Ubuntu');
os_release = chomp(os_release);
if (! ('24.04' >< os_release || '26.04' >< os_release || 'Pro' >< os_release)) audit(AUDIT_OS_NOT, 'Ubuntu 24.04 / 26.04 / Pro', 'Ubuntu ' + os_release);
if ( ! get_kb_item('Host/Debian/dpkg-l') ) 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, 'Ubuntu', cpu);

var pkgs = [
    {'osver': '24.04', 'pkgname': 'libnss-sudo', 'pkgver': '1.9.15p5-3ubuntu5.24.04.3'},
    {'osver': '24.04', 'pkgname': 'sudo', 'pkgver': '1.9.15p5-3ubuntu5.24.04.3'},
    {'osver': '24.04', 'pkgname': 'sudo-ldap', 'pkgver': '1.9.15p5-3ubuntu5.24.04.3'},
    {'osver': '26.04', 'pkgname': 'libnss-sudo', 'pkgver': '1.9.17p2-1ubuntu3.1'},
    {'osver': '26.04', 'pkgname': 'sudo', 'pkgver': '1.9.17p2-1ubuntu3.1'},
    {'osver': 'Pro', 'pkgname': 'libnss-sudo', 'pkgver': '1.9.15p5-3ubuntu5.24.04.3'},
    {'osver': 'Pro', 'pkgname': 'sudo', 'pkgver': '1.9.15p5-3ubuntu5.24.04.3'},
    {'osver': 'Pro', 'pkgname': 'sudo-ldap', 'pkgver': '1.9.15p5-3ubuntu5.24.04.3'}
];

var flag = 0;
foreach var package_array ( pkgs ) {
  var osver = NULL;
  var pkgname = NULL;
  var pkgver = NULL;
  if (!empty_or_null(package_array['osver'])) osver = package_array['osver'];
  if (!empty_or_null(package_array['pkgname'])) pkgname = package_array['pkgname'];
  if (!empty_or_null(package_array['pkgver'])) pkgver = package_array['pkgver'];
  if (!empty_or_null(package_array['cves'])) cves = package_array['cves'];
  if (osver && pkgname && pkgver) {
    if (deb_check(release:osver, prefix:pkgname, reference:pkgver, cves:cves)) flag++;
  }
}

if (flag)
{
  var extra = '';
  extra += ubuntu_report_get();
  security_report_v4(
    port       : 0,
    severity   : SECURITY_WARNING,
    extra      : extra
  );
  exit(0);
}
else
{
  var tested = ubuntu_pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'libnss-sudo / sudo / sudo-ldap');
}