Libreswan < 5.3.1 Multiple Vulnerabilities

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
##

include('compat.inc');

if (description)
{
  script_id(327415);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/07/16");

  script_cve_id("CVE-2026-50721", "CVE-2026-50722");

  script_name(english:"Libreswan < 5.3.1 Multiple Vulnerabilities");

  script_set_attribute(attribute:"synopsis", value:
"The version of Libreswan installed on the remote host is affected by multiple vulnerabilities.");
  script_set_attribute(attribute:"description", value:
"The version of Libreswan installed on the remote host is prior to 5.3.1. It is, therefore, affected by multiple
vulnerabilities:

  - Libreswan, via the function RSA_authenticate_hash_signature_raw_rsa(), did not correctly verify the length of the
    authentication hash when the SIG payload of an IKEv1 packet was encoded using PKCS #1 RSA Encryption as per RFC
    2313. A remote attacker can use a variation on the Bleichenbacher attack to forge the SIG payload when small public
    exponents are being used (e.g., e=3), which could lead to impersonation. Additionally, a remote attacker, by
    encoding a shorter than expected hash in the SIG payload, could trigger an assertion leading to
    denial-of-service. (CVE-2026-50721)

  - Libreswan, via the function RSA_authenticate_hash_signature_pkcs1_1_5_rsa(), did not correctly verify the DER
    encoding of the ASN.1 digest when the IKEv2 AUTH payload was encoded using RSASSA-PKCS1-v1_5 (RFC 8017). A remote
    attacker can use a variation on the Bleichenbacher attack to forge the AUTH payload when small public exponents are
    used (e.g., e=3), leading to impersonation. Additionally, a remote attacker, by encoding a shorter than expected
    hash in the AUTH payload, could trigger an assertion leading to denial-of-service. (CVE-2026-50722)

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://libreswan.org/security/CVE-2026-50721/CVE-2026-50721.txt");
  script_set_attribute(attribute:"see_also", value:"https://libreswan.org/security/CVE-2026-50722/CVE-2026-50722.txt");
  script_set_attribute(attribute:"solution", value:
"Upgrade to Libreswan version 5.3.1 or later.");
  script_set_attribute(attribute:"agent", value:"unix");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:H/Au:N/C:N/I:N/A:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-50721");

  script_set_attribute(attribute:"vuln_publication_date", value:"2026/06/24");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/06/24");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/07/16");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:libreswan:libreswan");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Misc.");

  script_copyright(english:"This script is Copyright (C) 2026 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("libreswan_nix_installed.nbin");
  script_require_keys("installed_sw/Libreswan");

  exit(0);
}

include('vcf.inc');

var app = 'Libreswan';

var app_info = vcf::get_app_info(app:app);
vcf::check_all_backporting(app_info:app_info);

var constraints = [
  { 'fixed_version' : '5.3.1' }
];

vcf::check_version_and_report(
  app_info:app_info,
  constraints:constraints,
  severity:SECURITY_WARNING
);