Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 26.04 LTS : Libwebsockets vulnerabilities (USN-8893-1)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-8893-1. 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(364280);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/08");

  script_cve_id("CVE-2026-19773");
  script_xref(name:"USN", value:"8893-1");

  script_name(english:"Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 26.04 LTS : Libwebsockets vulnerabilities (USN-8893-1)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Ubuntu host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"The remote Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 26.04 LTS host has packages installed that
are affected by a vulnerability as referenced in the USN-8893-1 advisory.

    It was discovered that libwebsockets did not properly validate user-supplied data when parsing HTTP/2
    HPACK path headers, which could result in a write past the end of an allocated buffer. An attacker could
    possibly use this issue to execute arbitrary code. (CVE-2026-19773)

    It was discovered that libwebsockets did not properly handle CBOR recording in the LECP parser, which
    could result in a write past the end of an allocated buffer. An attacker could possibly use this issue to
    cause a crash or execute arbitrary code. (CVE-2026-78161)

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-8893-1");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/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:N/AC:L/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-2026-19773");

  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:"2026/09/15");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/10/07");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/10/08");

  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:26.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libwebsockets-evlib-ev");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libwebsockets-evlib-glib");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libwebsockets-evlib-uv");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libwebsockets-test-server");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libwebsockets-test-server-common");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libwebsockets15");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libwebsockets16");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libwebsockets19t64");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libwebsockets7");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libwebsockets8");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  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_info2.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 || '26.04' >< os_release)) audit(AUDIT_OS_NOT, 'Ubuntu 16.04 / 18.04 / 20.04 / 22.04 / 24.04 / 26.04', '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': '16.04', 'pkgname': 'libwebsockets-test-server', 'pkgver': '1.7.1-1ubuntu0.1~esm1'},
    {'osver': '16.04', 'pkgname': 'libwebsockets-test-server-common', 'pkgver': '1.7.1-1ubuntu0.1~esm1'},
    {'osver': '16.04', 'pkgname': 'libwebsockets7', 'pkgver': '1.7.1-1ubuntu0.1~esm1'},
    {'osver': '18.04', 'pkgname': 'libwebsockets-test-server', 'pkgver': '2.0.3-3ubuntu0.1~esm1'},
    {'osver': '18.04', 'pkgname': 'libwebsockets-test-server-common', 'pkgver': '2.0.3-3ubuntu0.1~esm1'},
    {'osver': '18.04', 'pkgname': 'libwebsockets8', 'pkgver': '2.0.3-3ubuntu0.1~esm1'},
    {'osver': '20.04', 'pkgname': 'libwebsockets-test-server', 'pkgver': '3.2.1-3ubuntu0.1~esm3'},
    {'osver': '20.04', 'pkgname': 'libwebsockets-test-server-common', 'pkgver': '3.2.1-3ubuntu0.1~esm3'},
    {'osver': '20.04', 'pkgname': 'libwebsockets15', 'pkgver': '3.2.1-3ubuntu0.1~esm3'},
    {'osver': '22.04', 'pkgname': 'libwebsockets-test-server', 'pkgver': '4.0.20-2ubuntu1.1+esm2'},
    {'osver': '22.04', 'pkgname': 'libwebsockets-test-server-common', 'pkgver': '4.0.20-2ubuntu1.1+esm2'},
    {'osver': '22.04', 'pkgname': 'libwebsockets16', 'pkgver': '4.0.20-2ubuntu1.1+esm2'},
    {'osver': '24.04', 'pkgname': 'libwebsockets-evlib-ev', 'pkgver': '4.3.3-1.1ubuntu0.1~esm3'},
    {'osver': '24.04', 'pkgname': 'libwebsockets-evlib-glib', 'pkgver': '4.3.3-1.1ubuntu0.1~esm3'},
    {'osver': '24.04', 'pkgname': 'libwebsockets-evlib-uv', 'pkgver': '4.3.3-1.1ubuntu0.1~esm3'},
    {'osver': '24.04', 'pkgname': 'libwebsockets-test-server', 'pkgver': '4.3.3-1.1ubuntu0.1~esm3'},
    {'osver': '24.04', 'pkgname': 'libwebsockets-test-server-common', 'pkgver': '4.3.3-1.1ubuntu0.1~esm3'},
    {'osver': '24.04', 'pkgname': 'libwebsockets19t64', 'pkgver': '4.3.3-1.1ubuntu0.1~esm3'},
    {'osver': '26.04', 'pkgname': 'libwebsockets-evlib-ev', 'pkgver': '4.3.5-3ubuntu1.2+esm1'},
    {'osver': '26.04', 'pkgname': 'libwebsockets-evlib-glib', 'pkgver': '4.3.5-3ubuntu1.2+esm1'},
    {'osver': '26.04', 'pkgname': 'libwebsockets-evlib-uv', 'pkgver': '4.3.5-3ubuntu1.2+esm1'},
    {'osver': '26.04', 'pkgname': 'libwebsockets-test-server', 'pkgver': '4.3.5-3ubuntu1.2+esm1'},
    {'osver': '26.04', 'pkgname': 'libwebsockets-test-server-common', 'pkgver': '4.3.5-3ubuntu1.2+esm1'},
    {'osver': '26.04', 'pkgname': 'libwebsockets19t64', 'pkgver': '4.3.5-3ubuntu1.2+esm1'}
];

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_HOLE,
    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, 'libwebsockets-evlib-ev / libwebsockets-evlib-glib / etc');
}