Ubuntu 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 26.04 LTS : Cap'n Proto vulnerabilities (USN-8650-1)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-8650-1. 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(365438);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/13");

  script_cve_id("CVE-2026-32239", "CVE-2026-32240");
  script_xref(name:"USN", value:"8650-1");

  script_name(english:"Ubuntu 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 26.04 LTS : Cap'n Proto vulnerabilities (USN-8650-1)");

  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 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 26.04 LTS host has packages installed that are
affected by multiple vulnerabilities as referenced in the USN-8650-1 advisory.

    Chanho Kim and Jihyeok Han discovered that Cap'n Proto incorrectly handled negative Content-Length values
    or excessively large chunk sizes when processing HTTP messages. An attacker could possibly use these
    issues to cause HTTP messages to be interpreted inconsistently, resulting in HTTP request or response
    smuggling. (CVE-2026-32239, CVE-2026-32240)

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-8650-1");
  script_set_attribute(attribute:"solution", value:
"Update the affected 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:N/S:U/C:L/I:L/A:N");
  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:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/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-2026-32240");

  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:"2026/03/12");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/08/19");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/10/13");

  script_set_attribute(attribute:"plugin_type", value:"local");
  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:capnproto");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libcapnp-0.6.1");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libcapnp-0.7.0");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libcapnp-0.8.0");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libcapnp-1.0.1");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libcapnp-1.1.0");
  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 (! ('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 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': '18.04', 'pkgname': 'capnproto', 'pkgver': '0.6.1-1ubuntu1+esm1'},
    {'osver': '18.04', 'pkgname': 'libcapnp-0.6.1', 'pkgver': '0.6.1-1ubuntu1+esm1'},
    {'osver': '20.04', 'pkgname': 'capnproto', 'pkgver': '0.7.0-6ubuntu0.1~esm1'},
    {'osver': '20.04', 'pkgname': 'libcapnp-0.7.0', 'pkgver': '0.7.0-6ubuntu0.1~esm1'},
    {'osver': '22.04', 'pkgname': 'capnproto', 'pkgver': '0.8.0-2ubuntu2+esm1'},
    {'osver': '22.04', 'pkgname': 'libcapnp-0.8.0', 'pkgver': '0.8.0-2ubuntu2+esm1'},
    {'osver': '24.04', 'pkgname': 'capnproto', 'pkgver': '1.0.1-4ubuntu0.1~esm1'},
    {'osver': '24.04', 'pkgname': 'libcapnp-1.0.1', 'pkgver': '1.0.1-4ubuntu0.1~esm1'},
    {'osver': '26.04', 'pkgname': 'capnproto', 'pkgver': '1.1.0-2.1ubuntu0.1~esm1'},
    {'osver': '26.04', 'pkgname': 'libcapnp-1.1.0', 'pkgver': '1.1.0-2.1ubuntu0.1~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_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, 'capnproto / libcapnp-0.6.1 / libcapnp-0.7.0 / libcapnp-0.8.0 / etc');
}