Linux Distros Unpatched Vulnerability : CVE-2026-20339

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

include('compat.inc');

if (description)
{
  script_id(333538);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/08/08");

  script_cve_id("CVE-2026-20339");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2026-20339");

  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 vulnerability in the PESpin file format parser of ClamAV could allow an unauthenticated, remote attacker
    to cause a DoS condition or possibly other expanded impacts as a result ofmemory corruption on an
    affected device. This vulnerability is due to improper boundary checks for content in PESpin files during
    scanning, which may result in an integer overflow. An attacker could exploit this vulnerability by
    submitting a crafted file that contains PESpin content to be scanned by ClamAV on an affected device. A
    successful exploit could allow the attacker to cause the ClamAV scanning process to terminate, resulting
    in a DoS condition on the affected software. (CVE-2026-20339)

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-2026-20339");
  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:N/I:N/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:U/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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-2026-20339");

  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:"2026/08/07");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/08/08");

  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:clamav");
  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/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-12": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "12",
        "pkgs": [
          {"reference": "clamav"},
          {"reference": "clamav-base"},
          {"reference": "clamav-daemon"},
          {"reference": "clamav-doc"},
          {"reference": "clamav-docs"},
          {"reference": "clamav-freshclam"},
          {"reference": "clamav-milter"},
          {"reference": "clamav-testfiles"},
          {"reference": "clamdscan"},
          {"reference": "libclamav-dev"},
          {"reference": "libclamav12"}
        ]
      }
    ]
  },
  "Debian Linux-13": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "13",
        "pkgs": [
          {"reference": "clamav"},
          {"reference": "clamav-base"},
          {"reference": "clamav-daemon"},
          {"reference": "clamav-doc"},
          {"reference": "clamav-docs"},
          {"reference": "clamav-freshclam"},
          {"reference": "clamav-milter"},
          {"reference": "clamav-testfiles"},
          {"reference": "clamdscan"},
          {"reference": "libclamav-dev"},
          {"reference": "libclamav12"}
        ]
      }
    ]
  },
  "Debian Linux-14": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "14",
        "pkgs": [
          {"reference": "clamav"},
          {"reference": "clamav-base"},
          {"reference": "clamav-daemon"},
          {"reference": "clamav-doc"},
          {"reference": "clamav-docs"},
          {"reference": "clamav-freshclam"},
          {"reference": "clamav-milter"},
          {"reference": "clamav-testfiles"},
          {"reference": "clamdscan"},
          {"reference": "libclamav-dev"},
          {"reference": "libclamav12"}
        ]
      }
    ]
  },
  "Debian Linux-11": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "11",
        "pkgs": [
          {"reference": "clamav"},
          {"reference": "clamav-base"},
          {"reference": "clamav-daemon"},
          {"reference": "clamav-docs"},
          {"reference": "clamav-freshclam"},
          {"reference": "clamav-milter"},
          {"reference": "clamav-testfiles"},
          {"reference": "clamdscan"},
          {"reference": "libclamav-dev"},
          {"reference": "libclamav9"}
        ]
      }
    ]
  }
};

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 third_party_support = get_kb_item('Host/OS/extended-third-party');
if (!empty_or_null(third_party_support)) {
    var third_party_vendors = distro_constraints_values['third_party'];
    if (!empty_or_null(third_party_vendors)) {
        var vendor;
        foreach vendor (third_party_vendors) {
            if (vendor == third_party_support) exit(0, 'A third party management patch is available for this vulnerability from ' + vendor + '.\n');
        }
    }
}

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');
}