Linux Distros Unpatched Vulnerability : CVE-2026-23893

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

include('compat.inc');

if (description)
{
  script_id(297680);
  script_version("1.6");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/05/22");

  script_cve_id("CVE-2026-23893");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2026-23893");

  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.

  - openCryptoki is a PKCS#11 library and provides tooling for Linux and AIX. Versions 2.3.2 and above are
    vulnerable to symlink-following when running in privileged contexts. A token-group user can redirect file
    operations to arbitrary filesystem targets by planting symlinks in group-writable token directories,
    resulting in privilege escalation or data exposure. Token and lock directories are 0770 (group-writable
    for token users), so any token-group member can plant files and symlinks inside them. When run as root,
    the base code handling token directory file access, as well as several openCryptoki tools used for
    administrative purposes, may reset ownership or permissions on existing files inside the token
    directories. An attacker with token-group membership can exploit the system when an administrator runs a
    PKCS#11 application or administrative tool that performs chown on files inside the token directory during
    normal maintenance. This issue is fixed in commit 5e6e4b4, but has not been included in a released version
    at the time of publication. (CVE-2026-23893)

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-2026-23893");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2026-23893");
  script_set_attribute(attribute:"see_also", value:"https://ubuntu.com/security/CVE-2026-23893");
  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:L/AC:H/Au:S/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:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:L");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:U/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-23893");

  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:"2026/01/22");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/02/03");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:16.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:18.04:-:lts");
  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:"cpe:/o:canonical:ubuntu_linux:25.10");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:centos:centos:7");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:11.0");
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  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:13.0");
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  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:7");
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  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:opencryptoki");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:opencryptoki-ccatok");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:opencryptoki-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:opencryptoki-ep11tok");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:opencryptoki-icatok");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:opencryptoki-icsftok");
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  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:opencryptoki-swtok");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:opencryptoki-tpmtok");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:opencryptoki");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:opencryptoki");
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  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/Debian Linux-11", "Host/OS/Debian Linux-12", "Host/OS/Debian Linux-13", "Host/OS/Debian Linux-14", "Host/OS/Red Hat Enterprise Linux-6", "Host/OS/Red Hat Enterprise Linux-7", "Host/OS/Ubuntu Linux-16.04", "Host/OS/Ubuntu Linux-18.04", "Host/OS/Ubuntu Linux-20.04", "Host/OS/Ubuntu Linux-22.04", "Host/OS/Ubuntu Linux-24.04", "Host/OS/Ubuntu Linux-25.10");

  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/Debian/dpkg-l")) && empty_or_null(get_one_kb_item("Host/RedHat/rpm-list"))) 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": "libopencryptoki-dev"},
          {"reference": "libopencryptoki0"},
          {"reference": "opencryptoki"}
        ]
      }
    ]
  },
  "Debian Linux-12": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "12",
        "pkgs": [
          {"reference": "libopencryptoki-dev"},
          {"reference": "libopencryptoki0"},
          {"reference": "opencryptoki"}
        ]
      }
    ]
  },
  "Debian Linux-13": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "13",
        "pkgs": [
          {"reference": "libopencryptoki-dev"},
          {"reference": "libopencryptoki0"},
          {"reference": "opencryptoki"}
        ]
      }
    ]
  },
  "Debian Linux-14": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "14",
        "pkgs": [
          {"reference": "libopencryptoki-dev"},
          {"reference": "libopencryptoki0"},
          {"reference": "opencryptoki"}
        ]
      }
    ]
  },
  "Ubuntu Linux-16.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "16.04",
        "pkgs": [
          {"reference": "opencryptoki"}
        ]
      }
    ]
  },
  "Ubuntu Linux-18.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "18.04",
        "pkgs": [
          {"reference": "opencryptoki"}
        ]
      }
    ]
  },
  "Ubuntu Linux-20.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "20.04",
        "pkgs": [
          {"reference": "opencryptoki"}
        ]
      }
    ]
  },
  "Ubuntu Linux-22.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "22.04",
        "pkgs": [
          {"reference": "opencryptoki"}
        ]
      }
    ]
  },
  "Ubuntu Linux-24.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "24.04",
        "pkgs": [
          {"reference": "opencryptoki"}
        ]
      }
    ]
  },
  "Ubuntu Linux-25.10": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "25.10",
        "pkgs": [
          {"reference": "opencryptoki"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-6": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "6",
        "pkgs": [
          {"reference": "opencryptoki"},
          {"reference": "opencryptoki-devel"},
          {"reference": "opencryptoki-libs"}
        ]
      }
    ]
  },
  "CentOS Linux-7": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "7",
        "pkgs": [
          {"reference": "opencryptoki"},
          {"reference": "opencryptoki-ccatok"},
          {"reference": "opencryptoki-devel"},
          {"reference": "opencryptoki-ep11tok"},
          {"reference": "opencryptoki-icatok"},
          {"reference": "opencryptoki-icsftok"},
          {"reference": "opencryptoki-libs"},
          {"reference": "opencryptoki-swtok"},
          {"reference": "opencryptoki-tpmtok"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-7": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "7",
        "pkgs": [
          {"reference": "opencryptoki"},
          {"reference": "opencryptoki-ccatok"},
          {"reference": "opencryptoki-devel"},
          {"reference": "opencryptoki-ep11tok"},
          {"reference": "opencryptoki-icatok"},
          {"reference": "opencryptoki-icsftok"},
          {"reference": "opencryptoki-libs"},
          {"reference": "opencryptoki-swtok"},
          {"reference": "opencryptoki-tpmtok"}
        ]
      }
    ]
  }
};

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');
}