Linux Distros Unpatched Vulnerability : CVE-2018-6829

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

include('compat.inc');

if (description)
{
  script_id(258444);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/04/28");

  script_cve_id("CVE-2018-6829");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2018-6829");

  script_set_attribute(attribute:"synopsis", value:
"The Linux/Unix host has one or more packages installed with a vulnerability that the vendor indicates will not be
patched.");
  script_set_attribute(attribute:"description", value:
"The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied
patch available.

  - cipher/elgamal.c in Libgcrypt through 1.8.2, when used to encrypt messages directly, improperly encodes
    plaintexts, which allows attackers to obtain sensitive information by reading ciphertext data (i.e., it
    does not have semantic security in face of a ciphertext-only attack). The Decisional Diffie-Hellman (DDH)
    assumption does not hold for Libgcrypt's ElGamal implementation. (CVE-2018-6829)

Note that Nessus relies on the presence of the package as reported by the vendor.");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2018-6829");
  script_set_attribute(attribute:"solution", value:
"There is no known solution at this time.");
  script_set_attribute(attribute:"agent", value:"unix");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:N");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:U/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:U/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2018-6829");

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

  script_set_attribute(attribute:"vuln_publication_date", value:"2018/02/07");
  script_set_attribute(attribute:"plugin_publication_date", value:"2025/08/30");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:11.0");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:12.0");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:13.0");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:14.0");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:gnupg1");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libgcrypt20");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2025-2026 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info2.nasl", "set_linux_os_id.nasl");
  script_require_keys("Host/cpu", "Host/local_checks_enabled", "global_settings/vendor_unpatched", "Host/OS/identifier");
  script_require_ports("Host/OS/Debian Linux-11", "Host/OS/Debian Linux-12", "Host/OS/Debian Linux-13", "Host/OS/Debian Linux-14");

  exit(0);
}

if (!get_kb_item("global_settings/vendor_unpatched")) exit(0, "Unpatched Vulnerabilities Detection not active.");
if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (empty_or_null(get_one_kb_item("Host/Debian/dpkg-l"))) audit(AUDIT_PACKAGE_LIST_MISSING);

include('linux_unpatched.inc');

var distro_constraints_array = {
  "Debian Linux-11": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "11",
        "pkgs": [
          {"reference": "gnupg1"},
          {"reference": "gnupg1-l10n"},
          {"reference": "gpgv1"},
          {"reference": "libgcrypt-mingw-w64-dev"},
          {"reference": "libgcrypt20"},
          {"reference": "libgcrypt20-dev"},
          {"reference": "libgcrypt20-doc"},
          {"reference": "libgcrypt20-udeb"}
        ]
      }
    ]
  },
  "Debian Linux-12": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "12",
        "pkgs": [
          {"reference": "gnupg1"},
          {"reference": "gnupg1-l10n"},
          {"reference": "gpgv1"},
          {"reference": "libgcrypt-mingw-w64-dev"},
          {"reference": "libgcrypt20"},
          {"reference": "libgcrypt20-dev"},
          {"reference": "libgcrypt20-doc"},
          {"reference": "libgcrypt20-udeb"}
        ]
      }
    ]
  },
  "Debian Linux-13": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "13",
        "pkgs": [
          {"reference": "gnupg1"},
          {"reference": "gnupg1-l10n"},
          {"reference": "gpgv1"},
          {"reference": "libgcrypt-bin"},
          {"reference": "libgcrypt-mingw-w64-dev"},
          {"reference": "libgcrypt20"},
          {"reference": "libgcrypt20-dev"},
          {"reference": "libgcrypt20-doc"},
          {"reference": "libgcrypt20-udeb"}
        ]
      }
    ]
  },
  "Debian Linux-14": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "14",
        "pkgs": [
          {"reference": "gnupg1"},
          {"reference": "gnupg1-l10n"},
          {"reference": "gpgv1"},
          {"reference": "libgcrypt-bin"},
          {"reference": "libgcrypt-mingw-w64-dev"},
          {"reference": "libgcrypt20"},
          {"reference": "libgcrypt20-dev"},
          {"reference": "libgcrypt20-doc"},
          {"reference": "libgcrypt20-udeb"}
        ]
      }
    ]
  }
};

var distro_constraints_values = linux_unpatched::get_distro_constraints(distro_constraints_arr:distro_constraints_array);
if (empty_or_null(distro_constraints_values)) audit(AUDIT_HOST_NOT, 'affected');
var report = linux_unpatched::check_unpatched_constraints(distro_constraints_values:distro_constraints_values);

if (!empty_or_null(report))
{
  security_report_v4(
      port       : 0,
      severity   : SECURITY_WARNING,
      extra      : report
  );
  exit(0);
}
else
{
  audit(AUDIT_HOST_NOT, 'affected');
}