Ubuntu 24.04 LTS / 26.04 LTS / Pro Realtime 24.04 LTS : libssh2 vulnerabilities (USN-8722-1)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-8722-1. 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(344609);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/09/10");

  script_cve_id("CVE-2026-66032", "CVE-2026-66033", "CVE-2026-66035");
  script_xref(name:"USN", value:"8722-1");

  script_name(english:"Ubuntu 24.04 LTS / 26.04 LTS / Pro Realtime 24.04 LTS : libssh2 vulnerabilities (USN-8722-1)");

  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 24.04 LTS / 26.04 LTS / Pro Realtime 24.04 LTS host has a package installed that is affected by
multiple vulnerabilities as referenced in the USN-8722-1 advisory.

    It was discovered that libssh2 incorrectly handled certain SFTP server responses. A remote attacker
    controlling an SSH server could use this issue to cause libssh2 to crash or possibly execute arbitrary
    code. (CVE-2026-66032)

    It was discovered that libssh2 incorrectly handled AES-GCM cipher negotiation. A remote attacker
    controlling an SSH server could possibly use this issue to cause libssh2 to crash, resulting in a denial
    of service. (CVE-2026-66033)

    It was discovered that libssh2 incorrectly handled Encrypt-then-MAC cipher negotiation. A remote attacker
    controlling an SSH server could use this issue to cause libssh2 to crash or possibly execute arbitrary
    code. (CVE-2026-66035)

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-8722-1");
  script_set_attribute(attribute:"solution", value:
"Update the affected libssh2-1t64 package.");
  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:R/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:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/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-2026-66032");
  script_set_attribute(attribute:"cvss4_score_source", value:"CVE-2026-66033");

  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:"2026/07/24");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/09/03");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/09/10");

  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:libssh2-1t64");
  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_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': 'libssh2-1t64', 'pkgver': '1.11.0-4.1ubuntu0.24.04.4'},
    {'osver': '26.04', 'pkgname': 'libssh2-1t64', 'pkgver': '1.11.1-1ubuntu0.26.04.4'},
    {'osver': 'Pro', 'pkgname': 'libssh2-1t64', 'pkgver': '1.11.0-4.1ubuntu0.24.04.4'}
];

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, 'libssh2-1t64');
}