Ubuntu 20.04 LTS / 22.04 LTS / 23.04 / 23.10 : libssh vulnerabilities (USN-6592-1)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-6592-1. 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(189295);
  script_version("1.0");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/01/22");

  script_cve_id("CVE-2023-6004", "CVE-2023-6918");
  script_xref(name:"USN", value:"6592-1");

  script_name(english:"Ubuntu 20.04 LTS / 22.04 LTS / 23.04 / 23.10 : libssh vulnerabilities (USN-6592-1)");

  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 20.04 LTS / 22.04 LTS / 23.04 / 23.10 host has packages installed that are affected by multiple
vulnerabilities as referenced in the USN-6592-1 advisory.

  - A flaw was found in libssh. By utilizing the ProxyCommand or ProxyJump feature, users can exploit
    unchecked hostname syntax on the client. This issue may allow an attacker to inject malicious code into
    the command of the features mentioned through the hostname parameter. (CVE-2023-6004)

  - A flaw was found in the libssh implements abstract layer for message digest (MD) operations implemented by
    different supported crypto backends. The return values from these were not properly checked, which could
    cause low-memory situations failures, NULL dereferences, crashes, or usage of the uninitialized memory as
    an input for the KDF. In this case, non-matching keys will result in decryption/integrity failures,
    terminating the connection. (CVE-2023-6918)

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-6592-1");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:S/C:P/I:P/A:P");
  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:R/S:U/C:L/I:L/A:L");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2023-6004");

  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:"2023/12/19");
  script_set_attribute(attribute:"patch_publication_date", value:"2024/01/22");
  script_set_attribute(attribute:"plugin_publication_date", value:"2024/01/22");

  script_set_attribute(attribute:"plugin_type", value:"local");
  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:23.04");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:23.10");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libssh-4");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libssh-dev");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libssh-gcrypt-4");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libssh-gcrypt-dev");
  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) 2024 Canonical, Inc. / NASL script (C) 2024 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 (! ('20.04' >< os_release || '22.04' >< os_release || '23.04' >< os_release || '23.10' >< os_release)) audit(AUDIT_OS_NOT, 'Ubuntu 20.04 / 22.04 / 23.04 / 23.10', '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 pkgs = [
    {'osver': '20.04', 'pkgname': 'libssh-4', 'pkgver': '0.9.3-2ubuntu2.5'},
    {'osver': '20.04', 'pkgname': 'libssh-dev', 'pkgver': '0.9.3-2ubuntu2.5'},
    {'osver': '20.04', 'pkgname': 'libssh-gcrypt-4', 'pkgver': '0.9.3-2ubuntu2.5'},
    {'osver': '20.04', 'pkgname': 'libssh-gcrypt-dev', 'pkgver': '0.9.3-2ubuntu2.5'},
    {'osver': '22.04', 'pkgname': 'libssh-4', 'pkgver': '0.9.6-2ubuntu0.22.04.3'},
    {'osver': '22.04', 'pkgname': 'libssh-dev', 'pkgver': '0.9.6-2ubuntu0.22.04.3'},
    {'osver': '22.04', 'pkgname': 'libssh-gcrypt-4', 'pkgver': '0.9.6-2ubuntu0.22.04.3'},
    {'osver': '22.04', 'pkgname': 'libssh-gcrypt-dev', 'pkgver': '0.9.6-2ubuntu0.22.04.3'},
    {'osver': '23.04', 'pkgname': 'libssh-4', 'pkgver': '0.10.4-2ubuntu0.3'},
    {'osver': '23.04', 'pkgname': 'libssh-dev', 'pkgver': '0.10.4-2ubuntu0.3'},
    {'osver': '23.04', 'pkgname': 'libssh-gcrypt-4', 'pkgver': '0.10.4-2ubuntu0.3'},
    {'osver': '23.04', 'pkgname': 'libssh-gcrypt-dev', 'pkgver': '0.10.4-2ubuntu0.3'},
    {'osver': '23.10', 'pkgname': 'libssh-4', 'pkgver': '0.10.5-3ubuntu1.2'},
    {'osver': '23.10', 'pkgname': 'libssh-dev', 'pkgver': '0.10.5-3ubuntu1.2'},
    {'osver': '23.10', 'pkgname': 'libssh-gcrypt-4', 'pkgver': '0.10.5-3ubuntu1.2'},
    {'osver': '23.10', 'pkgname': 'libssh-gcrypt-dev', 'pkgver': '0.10.5-3ubuntu1.2'}
];

var flag = 0;
foreach 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 (osver && pkgname && pkgver) {
    if (ubuntu_check(osver:osver, pkgname:pkgname, pkgver:pkgver)) flag++;
  }
}

if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_WARNING,
    extra      : ubuntu_report_get()
  );
  exit(0);
}
else
{
  var tested = ubuntu_pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'libssh-4 / libssh-dev / libssh-gcrypt-4 / libssh-gcrypt-dev');
}