Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 25.04 / 25.10 : Tornado vulnerabilities (USN-7950-1)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-7950-1. 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(282532);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/04/30");

  script_cve_id("CVE-2025-67724", "CVE-2025-67725", "CVE-2025-67726");
  script_xref(name:"USN", value:"7950-1");
  script_xref(name:"IAVB", value:"2026-B-0009-S");

  script_name(english:"Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 25.04 / 25.10 : Tornado vulnerabilities (USN-7950-1)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Ubuntu host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The remote Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 25.04 / 25.10 host has packages installed
that are affected by multiple vulnerabilities as referenced in the USN-7950-1 advisory.

    It was discovered that Tornado incorrectly handled special characters in HTTP headers. An attacker could
    possibly use this issue to execute a cross- site scripting (XSS) attack. This issue only affected Ubuntu
    20.04 LTS, Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, Ubuntu 25.04, and Ubuntu 25.10. (CVE-2025-67724)

    It was discovered that Tornado incorrectly handled repeated HTTP headers. An attacker could possibly use
    this issue to cause Tornado to use excessive resources, causing a denial of service. (CVE-2025-67725)

    It was discovered that Tornado incorrectly handled parsing of certain HTTP header values. An attacker
    could possibly use this issue to cause Tornado to use excessive resources, causing a denial of service.
    (CVE-2025-67726)

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

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://ubuntu.com/security/notices/USN-7950-1");
  script_set_attribute(attribute:"solution", value:
"Update the affected python-tornado and / or python3-tornado packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:N");
  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:R/S:C/C:L/I:L/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2025-67724");

  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:"2025/12/12");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/01/08");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/01/09");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:16.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:18.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:20.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:22.04:-:lts");
  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:25.04");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:25.10");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:python-tornado");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:python3-tornado");
  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", "ubuntu_pro_sub_detect.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 (! ('16.04' >< os_release || '18.04' >< os_release || '20.04' >< os_release || '22.04' >< os_release || '24.04' >< os_release || '25.04' >< os_release || '25.10' >< os_release)) audit(AUDIT_OS_NOT, 'Ubuntu 16.04 / 18.04 / 20.04 / 22.04 / 24.04 / 25.04 / 25.10', '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 ubuntu_pro_detected = get_kb_item('Host/Ubuntu/Pro/Services/esm-apps');
ubuntu_pro_detected = !empty_or_null(ubuntu_pro_detected);

var pro_caveat_needed = FALSE;

var pkgs = [
    {'osver': '16.04', 'pkgname': 'python-tornado', 'pkgver': '4.2.1-1ubuntu3.1+esm2', 'ubuntu_pro': TRUE, 'cves': ['CVE-2025-67725', 'CVE-2025-67726']},
    {'osver': '16.04', 'pkgname': 'python3-tornado', 'pkgver': '4.2.1-1ubuntu3.1+esm2', 'ubuntu_pro': TRUE, 'cves': ['CVE-2025-67725', 'CVE-2025-67726']},
    {'osver': '18.04', 'pkgname': 'python-tornado', 'pkgver': '4.5.3-1ubuntu0.2+esm2', 'ubuntu_pro': TRUE, 'cves': ['CVE-2025-67725', 'CVE-2025-67726']},
    {'osver': '18.04', 'pkgname': 'python3-tornado', 'pkgver': '4.5.3-1ubuntu0.2+esm2', 'ubuntu_pro': TRUE, 'cves': ['CVE-2025-67725', 'CVE-2025-67726']},
    {'osver': '20.04', 'pkgname': 'python3-tornado', 'pkgver': '6.0.3+really5.1.1-3ubuntu0.1~esm3', 'ubuntu_pro': TRUE, 'cves': ['CVE-2025-67724', 'CVE-2025-67725', 'CVE-2025-67726']},
    {'osver': '22.04', 'pkgname': 'python3-tornado', 'pkgver': '6.1.0-3ubuntu0.1~esm4', 'ubuntu_pro': TRUE, 'cves': ['CVE-2025-67724', 'CVE-2025-67725', 'CVE-2025-67726']},
    {'osver': '24.04', 'pkgname': 'python3-tornado', 'pkgver': '6.4.0-1ubuntu0.4', 'ubuntu_pro': FALSE, 'cves': ['CVE-2025-67724', 'CVE-2025-67725', 'CVE-2025-67726']},
    {'osver': '25.04', 'pkgname': 'python3-tornado', 'pkgver': '6.4.2-1ubuntu0.25.04.3', 'ubuntu_pro': FALSE, 'cves': ['CVE-2025-67724', 'CVE-2025-67725', 'CVE-2025-67726']},
    {'osver': '25.10', 'pkgname': 'python3-tornado', 'pkgver': '6.4.2-3ubuntu0.2', 'ubuntu_pro': FALSE, 'cves': ['CVE-2025-67724', 'CVE-2025-67725', 'CVE-2025-67726']}
];

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

if (flag)
{
  var extra = '';
  if (pro_caveat_needed) {
    extra += 'NOTE: This vulnerability check contains fixes that apply to packages only \n';
    extra += 'available in Ubuntu ESM repositories. Access to these package security updates \n';
    extra += 'require an Ubuntu Pro subscription.\n\n';
  }
  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, 'python-tornado / python3-tornado');
}