Linux Distros Unpatched Vulnerability : CVE-2025-0686

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

include('compat.inc');

if (description)
{
  script_id(232120);
  script_version("1.9");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/05/22");

  script_cve_id("CVE-2025-0686");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2025-0686");

  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 grub2. When performing a symlink lookup from a romfs filesystem, grub's romfs
    filesystem module uses user-controlled parameters from the filesystem geometry to determine the internal
    buffer size, however, it improperly checks for integer overflows. A maliciously crafted filesystem may
    lead some of those buffer size calculations to overflow, causing it to perform a grub_malloc() operation
    with a smaller size than expected. As a result, the grub_romfs_read_symlink() may cause out-of-bounds
    writes when the calling grub_disk_read() function. This issue may be leveraged to corrupt grub's internal
    critical data and can result in arbitrary code execution by-passing secure boot protections.
    (CVE-2025-0686)

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-2025-0686");
  script_set_attribute(attribute:"see_also", value:"https://ubuntu.com/security/CVE-2025-0686");
  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:L/Au:N/C:C/I:C/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:U/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:H/PR:H/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-2025-0686");

  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:"2025/03/03");
  script_set_attribute(attribute:"plugin_publication_date", value:"2025/03/06");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:14.04:-:lts");
  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:25.04");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:25.10");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:11.0");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:grub2");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:grub2-signed");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:grub2-unsigned");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:grub2");
  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("set_linux_os_id.nasl", "ssh_get_info2.nasl");
  script_require_keys("Host/OS/identifier", "Host/cpu", "Host/local_checks_enabled", "global_settings/vendor_unpatched");
  script_require_ports("Host/OS/Debian Linux-11", "Host/OS/Ubuntu Linux-14.04", "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-25.04", "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/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": "grub-common"},
          {"reference": "grub-coreboot"},
          {"reference": "grub-coreboot-bin"},
          {"reference": "grub-coreboot-dbg"},
          {"reference": "grub-efi"},
          {"reference": "grub-efi-amd64"},
          {"reference": "grub-efi-amd64-bin"},
          {"reference": "grub-efi-amd64-dbg"},
          {"reference": "grub-efi-amd64-signed-template"},
          {"reference": "grub-efi-arm"},
          {"reference": "grub-efi-arm-bin"},
          {"reference": "grub-efi-arm-dbg"},
          {"reference": "grub-efi-arm64"},
          {"reference": "grub-efi-arm64-bin"},
          {"reference": "grub-efi-arm64-dbg"},
          {"reference": "grub-efi-arm64-signed-template"},
          {"reference": "grub-efi-ia32"},
          {"reference": "grub-efi-ia32-bin"},
          {"reference": "grub-efi-ia32-dbg"},
          {"reference": "grub-efi-ia32-signed-template"},
          {"reference": "grub-efi-ia64"},
          {"reference": "grub-efi-ia64-bin"},
          {"reference": "grub-efi-ia64-dbg"},
          {"reference": "grub-emu"},
          {"reference": "grub-emu-dbg"},
          {"reference": "grub-firmware-qemu"},
          {"reference": "grub-ieee1275"},
          {"reference": "grub-ieee1275-bin"},
          {"reference": "grub-ieee1275-dbg"},
          {"reference": "grub-linuxbios"},
          {"reference": "grub-mount-udeb"},
          {"reference": "grub-pc"},
          {"reference": "grub-pc-bin"},
          {"reference": "grub-pc-dbg"},
          {"reference": "grub-rescue-pc"},
          {"reference": "grub-theme-starfield"},
          {"reference": "grub-uboot"},
          {"reference": "grub-uboot-bin"},
          {"reference": "grub-uboot-dbg"},
          {"reference": "grub-xen"},
          {"reference": "grub-xen-bin"},
          {"reference": "grub-xen-dbg"},
          {"reference": "grub-xen-host"},
          {"reference": "grub-yeeloong"},
          {"reference": "grub-yeeloong-bin"},
          {"reference": "grub-yeeloong-dbg"},
          {"reference": "grub2"},
          {"reference": "grub2-common"}
        ]
      }
    ]
  },
  "Ubuntu Linux-14.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "14.04",
        "pkgs": [
          {"reference": "grub-common"},
          {"reference": "grub-coreboot"},
          {"reference": "grub-coreboot-bin"},
          {"reference": "grub-coreboot-dbg"},
          {"reference": "grub-efi"},
          {"reference": "grub-efi-amd64"},
          {"reference": "grub-efi-amd64-bin"},
          {"reference": "grub-efi-amd64-dbg"},
          {"reference": "grub-efi-amd64-signed"},
          {"reference": "grub-efi-arm"},
          {"reference": "grub-efi-arm-bin"},
          {"reference": "grub-efi-arm-dbg"},
          {"reference": "grub-efi-arm64"},
          {"reference": "grub-efi-arm64-bin"},
          {"reference": "grub-efi-arm64-dbg"},
          {"reference": "grub-efi-ia32"},
          {"reference": "grub-efi-ia32-bin"},
          {"reference": "grub-efi-ia32-dbg"},
          {"reference": "grub-efi-ia64"},
          {"reference": "grub-efi-ia64-bin"},
          {"reference": "grub-efi-ia64-dbg"},
          {"reference": "grub-emu"},
          {"reference": "grub-emu-dbg"},
          {"reference": "grub-firmware-qemu"},
          {"reference": "grub-ieee1275"},
          {"reference": "grub-ieee1275-bin"},
          {"reference": "grub-ieee1275-dbg"},
          {"reference": "grub-linuxbios"},
          {"reference": "grub-mount-udeb"},
          {"reference": "grub-pc"},
          {"reference": "grub-pc-bin"},
          {"reference": "grub-pc-dbg"},
          {"reference": "grub-rescue-pc"},
          {"reference": "grub-theme-starfield"},
          {"reference": "grub-uboot"},
          {"reference": "grub-uboot-bin"},
          {"reference": "grub-uboot-dbg"},
          {"reference": "grub-xen"},
          {"reference": "grub-xen-bin"},
          {"reference": "grub-xen-dbg"},
          {"reference": "grub-yeeloong"},
          {"reference": "grub-yeeloong-bin"},
          {"reference": "grub-yeeloong-dbg"},
          {"reference": "grub2"},
          {"reference": "grub2-common"}
        ]
      }
    ]
  },
  "Ubuntu Linux-16.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "16.04",
        "pkgs": [
          {"reference": "grub-efi-amd64-signed"},
          {"reference": "grub-efi-arm64-signed"},
          {"reference": "grub2-unsigned"}
        ]
      }
    ]
  },
  "Ubuntu Linux-18.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "18.04",
        "pkgs": [
          {"reference": "grub-efi-amd64-signed"},
          {"reference": "grub-efi-arm64-signed"},
          {"reference": "grub2-unsigned"}
        ]
      }
    ]
  },
  "Ubuntu Linux-20.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "20.04",
        "pkgs": [
          {"reference": "grub-efi-amd64-signed"},
          {"reference": "grub-efi-arm64-signed"},
          {"reference": "grub2-unsigned"}
        ]
      }
    ]
  },
  "Ubuntu Linux-22.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "22.04",
        "pkgs": [
          {"reference": "grub-efi-amd64"},
          {"reference": "grub-efi-amd64-bin"},
          {"reference": "grub-efi-amd64-dbg"},
          {"reference": "grub-efi-amd64-signed"},
          {"reference": "grub-efi-arm64"},
          {"reference": "grub-efi-arm64-bin"},
          {"reference": "grub-efi-arm64-dbg"},
          {"reference": "grub-efi-arm64-signed"}
        ]
      }
    ]
  },
  "Ubuntu Linux-24.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "24.04",
        "pkgs": [
          {"reference": "grub-efi-amd64"},
          {"reference": "grub-efi-amd64-bin"},
          {"reference": "grub-efi-amd64-dbg"},
          {"reference": "grub-efi-amd64-signed"},
          {"reference": "grub-efi-arm64"},
          {"reference": "grub-efi-arm64-bin"},
          {"reference": "grub-efi-arm64-dbg"},
          {"reference": "grub-efi-arm64-signed"}
        ]
      }
    ]
  },
  "Ubuntu Linux-25.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "25.04",
        "pkgs": [
          {"reference": "grub-efi-amd64"},
          {"reference": "grub-efi-amd64-bin"},
          {"reference": "grub-efi-amd64-dbg"},
          {"reference": "grub-efi-amd64-signed"},
          {"reference": "grub-efi-amd64-unsigned"},
          {"reference": "grub-efi-arm64"},
          {"reference": "grub-efi-arm64-bin"},
          {"reference": "grub-efi-arm64-dbg"},
          {"reference": "grub-efi-arm64-signed"},
          {"reference": "grub-efi-arm64-unsigned"}
        ]
      }
    ]
  },
  "Ubuntu Linux-25.10": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "25.10",
        "pkgs": [
          {"reference": "grub-efi-amd64"},
          {"reference": "grub-efi-amd64-bin"},
          {"reference": "grub-efi-amd64-dbg"},
          {"reference": "grub-efi-amd64-signed"},
          {"reference": "grub-efi-amd64-unsigned"},
          {"reference": "grub-efi-arm64"},
          {"reference": "grub-efi-arm64-bin"},
          {"reference": "grub-efi-arm64-dbg"},
          {"reference": "grub-efi-arm64-signed"},
          {"reference": "grub-efi-arm64-unsigned"}
        ]
      }
    ]
  }
};

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');
}