Xen: A transaction conflict can crash C Xenstored (XSA-440)

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

include('compat.inc');

if (description)
{
  script_id(182974);
  script_version("1.5");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/01/15");

  script_cve_id("CVE-2023-34323");
  script_xref(name:"IAVB", value:"2023-B-0081-S");

  script_name(english:"Xen: A transaction conflict can crash C Xenstored (XSA-440)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Xen hypervisor installation is missing a security update.");
  script_set_attribute(attribute:"description", value:
"When a transaction is committed, C Xenstored will first check the quota is correct before attempting to commit 
any nodes. It would be possible that accounting is temporarily negative if a node has been removed outside of the 
transaction.

Unfortunately, some versions of C Xenstored are assuming that the quota cannot be negative and are using assert() to 
confirm it. This will lead to C Xenstored crash when tools are built without -DNDEBUG (this is the default).

A malicious guest could craft a transaction that will hit the C Xenstored bug and crash it. This will result to the 
inability to perform any further domain administration like starting new guests, or adding/removing resources to or 
from any existing guest.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version   
number.");
  script_set_attribute(attribute:"see_also", value:"https://xenbits.xen.org/xsa/advisory-440.html");
  script_set_attribute(attribute:"solution", value:
"Apply the appropriate patch according to the vendor advisory.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:S/C:N/I:N/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2023-34323");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");

  script_set_attribute(attribute:"vuln_publication_date", value:"2023/10/10");
  script_set_attribute(attribute:"patch_publication_date", value:"2023/10/10");
  script_set_attribute(attribute:"plugin_publication_date", value:"2023/10/12");

  script_set_attribute(attribute:"potential_vulnerability", value:"true");
  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:xen:xen");
  script_set_attribute(attribute:"stig_severity", value:"I");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Misc.");

  script_copyright(english:"This script is Copyright (C) 2023-2024 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("xen_server_detect.nbin");
  script_require_keys("installed_sw/Xen Hypervisor", "Settings/ParanoidReport");

  exit(0);
}

include('vcf.inc');
include('vcf_extras.inc');

var fixes;
var app = 'Xen Hypervisor';
var app_info = vcf::xen_hypervisor::get_app_info(app:app);
if (report_paranoia < 2) audit(AUDIT_PARANOID);

fixes['4.15']['fixed_ver']           = '4.15.5';
fixes['4.15']['fixed_ver_display']   = '4.15.5 (changeset 0a70ce9)';
fixes['4.15']['affected_ver_regex']  = "^4\.15([^0-9]|$)";
fixes['4.15']['affected_changesets'] = make_list('3a9a290', 'd7b7804',
  'b007f82', 'dac9060', 'd39e5cf', 'd75cb6d', '93504b3', '67b9743', 
  '806893a', '094cd5c', 'db3386e', '0517763', 'da7f151');

fixes['4.17']['fixed_ver']           = '4.17.3';
fixes['4.17']['fixed_ver_display']   = '4.17.3-pre (changeset c4e05c9)';
fixes['4.17']['affected_ver_regex']  = "^4\.17([^0-9]|$)";
fixes['4.17']['affected_changesets'] = make_list('90c540c', '9ac2f49',
  '19ee1e1', '2e2c3ef', 'e4a71bc', '5f7efd4', 'ba023e9', '3952c73', 
  '84690fb', 'dc28aba', 'd2d2dca', 'd31e5b2', '699de51', '8be85d8', 
  'a939e95', '7ca58fb', '0429822', 'ba360fb', '5116fe1', 'e08e733', 
  '1bd4523', 'a885649', 'd0cdd34', 'f04295d', 'e5f9987', '7b5155a', 
  '052a8d2', 'f00d563', 'e418a77', '24487fe', 'ae1045c', '37f1d68', 
  '476d262', 'a1f68fb', '36e84ea', '56076ef', '1c3927f', '8d84be5', 
  '7d88979', '2f337a0');

vcf::xen_hypervisor::check_version_and_report(app_info:app_info, fixes:fixes, severity:SECURITY_WARNING);