Citrix XenServer 8.4.x / 9.x Multiple Vulnerabilities (CTX697170)

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

include('compat.inc');

if (description)
{
  script_id(370480);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/22");

  script_cve_id("CVE-2026-79610", "CVE-2026-79611", "CVE-2026-102701");

  script_name(english:"Citrix XenServer 8.4.x / 9.x Multiple Vulnerabilities (CTX697170)");

  script_set_attribute(attribute:"synopsis", value:
"A server virtualization platform installed on the remote host is affected by multiple vulnerabilities.");
  script_set_attribute(attribute:"description", value:
"The version of Citrix XenServer installed on the remote host is 8.4.x or 9.x. It is, therefore, affected by multiple
vulnerabilities as referenced in the CTX697170 advisory:

  - A grant table race on a v2 -> v1 -> v2 version change may allow a privileged user in a guest VM to compromise
    or crash the host. (CVE-2026-79610)

  - A vulnerability in tapdisk may allow a privileged user in a guest VM to compromise or crash the host.
    (CVE-2026-102701)

  - A VMX VMentry failure with branch tracing and blocked states may allow an unprivileged user in a guest VM to
    crash that guest VM. (CVE-2026-79611)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported
version number. The vendor delivers this update through the XenServer update channels without changing the reported
product version, so Nessus cannot determine whether the update has been applied.");
  # https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX697170
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?1e3ee795");
  script_set_attribute(attribute:"see_also", value:"https://xenbits.xenproject.org/xsa/advisory-517.html");
  script_set_attribute(attribute:"see_also", value:"https://xenbits.xenproject.org/xsa/advisory-518.html");
  script_set_attribute(attribute:"see_also", value:"https://xenbits.xenproject.org/xsa/advisory-521.html");
  script_set_attribute(attribute:"solution", value:
"Apply the latest updates from the Early Access or Normal update channel of XenServer 8.4 or XenServer 9 as described
in the vendor advisory.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:S/C:C/I:C/A:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-79610");

  script_cwe_id(362, 843);

  script_set_attribute(attribute:"vuln_publication_date", value:"2026/10/13");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/10/13");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/10/22");

  script_set_attribute(attribute:"potential_vulnerability", value:"true");
  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:citrix:xenserver");
  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("citrix_xenserver_version.nbin");
  script_require_keys("Host/XenServer/version", "Host/local_checks_enabled", "Settings/ParanoidReport");

  exit(0);
}

include('vcf_extras.inc');

var app_info = vcf::xenserver::get_app_info();

if (report_paranoia < 2) audit(AUDIT_PARANOID);

var constraints = [
  { 'min_version' : '8.4', 'max_version' : '8.4.99999', 'fixed_display' : 'See vendor advisory' },
  { 'min_version' : '9', 'max_version' : '9.99999', 'fixed_display' : 'See vendor advisory' }
];

vcf::xenserver::check_version_and_report(
  app_info:app_info,
  constraints:constraints,
  severity:SECURITY_WARNING
);