Linux Distros Unpatched Vulnerability : CVE-2026-6893

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

include('compat.inc');

if (description)
{
  script_id(320498);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/06/12");

  script_cve_id("CVE-2026-6893");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2026-6893");

  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.

  - A flaw was found in dracut. A remote attacker on the adjacent network can exploit this vulnerability by
    providing specially crafted DHCP (Dynamic Host Configuration Protocol) options, such as a malicious
    hostname, to a system using dracut's legacy DHCP path. These options are improperly handled and written
    into temporary shell scripts without proper escaping, leading to command injection. This allows the
    attacker to achieve root code execution within the initramfs, potentially compromising the system's boot
    and network behavior. (CVE-2026-6893)

Note that Nessus relies on the presence of the package as reported by the vendor.");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/security/cve/cve-2026-6893");
  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:A/AC:L/Au:N/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:U/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:U/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-6893");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");
  script_set_attribute(attribute:"vendor_unpatched", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2026/06/10");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/06/11");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:centos:centos:7");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:centos:centos:8");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:10");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:7");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:8");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:9");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:dracut");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:dracut-caps");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:dracut-config-generic");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:dracut-config-rescue");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:dracut-fips");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:dracut-fips-aesni");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:dracut-live");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:dracut-network");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:dracut-squash");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:dracut-tools");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:dracut");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:dracut-caps");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:dracut-config-generic");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:dracut-config-rescue");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:dracut-fips");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:dracut-fips-aesni");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:dracut-live");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:dracut-network");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:dracut-squash");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:dracut-tools");
  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) 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/CentOS Linux-7", "Host/OS/CentOS Linux-8", "Host/OS/Red Hat Enterprise Linux-10", "Host/OS/Red Hat Enterprise Linux-7", "Host/OS/Red Hat Enterprise Linux-8", "Host/OS/Red Hat Enterprise Linux-9");

  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/CentOS/rpm-list")) && empty_or_null(get_one_kb_item("Host/RedHat/rpm-list"))) audit(AUDIT_PACKAGE_LIST_MISSING);

include('linux_unpatched.inc');

var distro_constraints_array = {
  "CentOS Linux-8": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "8",
        "pkgs": [
          {"reference": "dracut"},
          {"reference": "dracut-caps"},
          {"reference": "dracut-config-generic"},
          {"reference": "dracut-config-rescue"},
          {"reference": "dracut-live"},
          {"reference": "dracut-network"},
          {"reference": "dracut-squash"},
          {"reference": "dracut-tools"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-10": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "10",
        "pkgs": [
          {"reference": "dracut"},
          {"reference": "dracut-caps"},
          {"reference": "dracut-config-generic"},
          {"reference": "dracut-config-rescue"},
          {"reference": "dracut-live"},
          {"reference": "dracut-network"},
          {"reference": "dracut-squash"},
          {"reference": "dracut-tools"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-8": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "8",
        "pkgs": [
          {"reference": "dracut"},
          {"reference": "dracut-caps"},
          {"reference": "dracut-config-generic"},
          {"reference": "dracut-config-rescue"},
          {"reference": "dracut-live"},
          {"reference": "dracut-network"},
          {"reference": "dracut-squash"},
          {"reference": "dracut-tools"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-9": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "9",
        "pkgs": [
          {"reference": "dracut"},
          {"reference": "dracut-caps"},
          {"reference": "dracut-config-generic"},
          {"reference": "dracut-config-rescue"},
          {"reference": "dracut-live"},
          {"reference": "dracut-network"},
          {"reference": "dracut-squash"},
          {"reference": "dracut-tools"}
        ]
      }
    ]
  },
  "CentOS Linux-7": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "7",
        "pkgs": [
          {"reference": "dracut"},
          {"reference": "dracut-caps"},
          {"reference": "dracut-config-generic"},
          {"reference": "dracut-config-rescue"},
          {"reference": "dracut-fips"},
          {"reference": "dracut-fips-aesni"},
          {"reference": "dracut-network"},
          {"reference": "dracut-tools"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-7": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "7",
        "pkgs": [
          {"reference": "dracut"},
          {"reference": "dracut-caps"},
          {"reference": "dracut-config-generic"},
          {"reference": "dracut-config-rescue"},
          {"reference": "dracut-fips"},
          {"reference": "dracut-fips-aesni"},
          {"reference": "dracut-network"},
          {"reference": "dracut-tools"}
        ]
      }
    ]
  }
};

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_HOLE,
      extra      : report
  );
  exit(0);
}
else
{
  audit(AUDIT_HOST_NOT, 'affected');
}