Linux Distros Unpatched Vulnerability : CVE-2026-84267

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

include('compat.inc');

if (description)
{
  script_id(342198);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/09/01");

  script_cve_id("CVE-2026-84267");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2026-84267");

  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 the SFTP backend in gvfs. When mounting a share, a malicious SFTP server can cause
    read_string() to allocate a buffer with a certain length but the function does not verify that the buffer
    is completely filled, leaving the remainder of the buffer containing uninitialized heap contents. If the
    server sends a short FXP_HANDLE reply, these uninitialized bytes are taken as the file handle. The client
    will then echo these uninitialized bytes back to the server on all subsequent requests using that handle.
    With a length of 128 bytes, this issue allows the malicious server to deterministically read uninitialized
    heap memory from the gvfsd-sftp process, leaking its heap base and the load address of the libgio library,
    resulting in a deterministic defeat of Address Space Layout Randomization (ASLR). (CVE-2026-84267)

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-2026-84267");
  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:U/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:U/RL:U/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-84267");

  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:"2026/09/01");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/09/01");

  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:gvfs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:gvfs-afc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:gvfs-afp");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:gvfs-archive");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:gvfs-client");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:gvfs-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:gvfs-fuse");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:gvfs-goa");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:gvfs-gphoto2");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:gvfs-mtp");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:gvfs-smb");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:gvfs-tests");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:gvfs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:gvfs-afc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:gvfs-afp");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:gvfs-archive");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:gvfs-client");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:gvfs-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:gvfs-fuse");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:gvfs-goa");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:gvfs-gphoto2");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:gvfs-mtp");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:gvfs-smb");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:gvfs-tests");
  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 = {
  "Red Hat Enterprise Linux-10": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "10",
        "pkgs": [
          {"reference": "gvfs"},
          {"reference": "gvfs-client"},
          {"reference": "gvfs-fuse"},
          {"reference": "gvfs-goa"},
          {"reference": "gvfs-gphoto2"},
          {"reference": "gvfs-mtp"},
          {"reference": "gvfs-smb"}
        ]
      }
    ]
  },
  "CentOS Linux-7": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "7",
        "pkgs": [
          {"reference": "gvfs"},
          {"reference": "gvfs-afc"},
          {"reference": "gvfs-afp"},
          {"reference": "gvfs-archive"},
          {"reference": "gvfs-client"},
          {"reference": "gvfs-devel"},
          {"reference": "gvfs-fuse"},
          {"reference": "gvfs-goa"},
          {"reference": "gvfs-gphoto2"},
          {"reference": "gvfs-mtp"},
          {"reference": "gvfs-smb"},
          {"reference": "gvfs-tests"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-7": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "7",
        "pkgs": [
          {"reference": "gvfs"},
          {"reference": "gvfs-afc"},
          {"reference": "gvfs-afp"},
          {"reference": "gvfs-archive"},
          {"reference": "gvfs-client"},
          {"reference": "gvfs-devel"},
          {"reference": "gvfs-fuse"},
          {"reference": "gvfs-goa"},
          {"reference": "gvfs-gphoto2"},
          {"reference": "gvfs-mtp"},
          {"reference": "gvfs-smb"},
          {"reference": "gvfs-tests"}
        ]
      }
    ]
  },
  "CentOS Linux-8": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "8",
        "pkgs": [
          {"reference": "gvfs"},
          {"reference": "gvfs-afc"},
          {"reference": "gvfs-afp"},
          {"reference": "gvfs-archive"},
          {"reference": "gvfs-client"},
          {"reference": "gvfs-devel"},
          {"reference": "gvfs-fuse"},
          {"reference": "gvfs-goa"},
          {"reference": "gvfs-gphoto2"},
          {"reference": "gvfs-mtp"},
          {"reference": "gvfs-smb"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-8": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "8",
        "pkgs": [
          {"reference": "gvfs"},
          {"reference": "gvfs-afc"},
          {"reference": "gvfs-afp"},
          {"reference": "gvfs-archive"},
          {"reference": "gvfs-client"},
          {"reference": "gvfs-devel"},
          {"reference": "gvfs-fuse"},
          {"reference": "gvfs-goa"},
          {"reference": "gvfs-gphoto2"},
          {"reference": "gvfs-mtp"},
          {"reference": "gvfs-smb"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-9": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "9",
        "pkgs": [
          {"reference": "gvfs"},
          {"reference": "gvfs-client"},
          {"reference": "gvfs-devel"},
          {"reference": "gvfs-fuse"},
          {"reference": "gvfs-goa"},
          {"reference": "gvfs-gphoto2"},
          {"reference": "gvfs-mtp"},
          {"reference": "gvfs-smb"}
        ]
      }
    ]
  }
};

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');
}