Ubuntu 20.04 LTS / 22.04 LTS / 24.04 LTS : AsyncSSH vulnerabilities (USN-7108-1)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-7108-1. 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(210948);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/11/18");

  script_cve_id("CVE-2023-46445", "CVE-2023-46446");
  script_xref(name:"USN", value:"7108-1");

  script_name(english:"Ubuntu 20.04 LTS / 22.04 LTS / 24.04 LTS : AsyncSSH vulnerabilities (USN-7108-1)");

  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 / 24.04 LTS host has a package installed that is affected by multiple
vulnerabilities as referenced in the USN-7108-1 advisory.

    Fabian Bumer, Marcus Brinkmann, and Jrg Schwenk discovered that AsyncSSH did not properly handle the
    extension info message. An attacker able to intercept communications could possibly use this issue to
    downgrade the algorithm used for client authentication. (CVE-2023-46445)

    Fabian Bumer, Marcus Brinkmann, and Jrg Schwenk discovered that AsyncSSH did not properly handle the
    user authentication request message. An attacker could possibly use this issue to control the remote end
    of an SSH client session via packet injection/removal and shell emulation. (CVE-2023-46446)

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-7108-1");
  script_set_attribute(attribute:"solution", value:
"Update the affected python3-asyncssh package.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:H/Au:S/C:C/I:C/A:N");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2023-46446");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2023/11/09");
  script_set_attribute(attribute:"patch_publication_date", value:"2024/11/14");
  script_set_attribute(attribute:"plugin_publication_date", value:"2024/11/14");

  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:24.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:python3-asyncssh");
  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", "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 (! ('20.04' >< os_release || '22.04' >< os_release || '24.04' >< os_release)) audit(AUDIT_OS_NOT, 'Ubuntu 20.04 / 22.04 / 24.04', '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 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': '20.04', 'pkgname': 'python3-asyncssh', 'pkgver': '1.12.2-1ubuntu0.2', 'ubuntu_pro': FALSE},
    {'osver': '22.04', 'pkgname': 'python3-asyncssh', 'pkgver': '2.5.0-1ubuntu0.1', 'ubuntu_pro': FALSE},
    {'osver': '24.04', 'pkgname': 'python3-asyncssh', 'pkgver': '2.10.1-2ubuntu0.1+esm1', 'ubuntu_pro': TRUE}
];

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'];
  var pro_required = NULL;
  if (!empty_or_null(package_array['ubuntu_pro'])) pro_required = package_array['ubuntu_pro'];
  if (osver && pkgname && pkgver) {
    if (ubuntu_check(osver:osver, pkgname:pkgname, pkgver:pkgver)) {
        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, 'python3-asyncssh');
}