KB5004948: Windows 10 1607 and Windows Server 2016 OOB Security Update RCE (July 2021)

2021-07-08T00:00:00
ID SMB_NT_MS21_JUL_5004948.NASL
Type nessus
Reporter This script is Copyright (C) 2021 and is owned by Tenable, Inc. or an Affiliate thereof.
Modified 2021-07-08T00:00:00

Description

A remote command execution vulnerability exists in Windows Print Spooler service improperly performs privileged file operations. An authenticated, remote attacker can exploit this to bypass and run arbitrary code with SYSTEM privileges.

                                        
                                            #%NASL_MIN_LEVEL 70300
##
# (C) Tenable Network Security, Inc.

#
# The descriptive text and package checks in this plugin were
# extracted from the Microsoft Security Updates API. The text
# itself is copyright (C) Microsoft Corporation.
##

include('deprecated_nasl_level.inc');

include('compat.inc');

if (description)
{
  script_id(151474);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2021/07/09");

  script_cve_id("CVE-2021-34527");
  script_xref(name:"IAVA", value:"2021-A-0299");
  script_xref(name:"MSKB", value:"5004948");
  script_xref(name:"MSFT", value:"MS21-5004948");

  script_name(english:"KB5004948: Windows 10 1607 and Windows Server 2016 OOB Security Update RCE (July 2021)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Windows host is affected by a remote code execution vulnerabilty.");
  script_set_attribute(attribute:"description", value:
"A remote command execution vulnerability exists in Windows Print Spooler service improperly performs privileged file 
operations. An authenticated, remote attacker can exploit this to bypass and run arbitrary code with SYSTEM privileges.");
  script_set_attribute(attribute:"see_also", value:"https://support.microsoft.com/en-us/help/5004948");
  script_set_attribute(attribute:"solution", value:
"Apply Cumulative Update 5004948");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:H/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:H/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2021-34527");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");
  script_set_attribute(attribute:"exploited_by_malware", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2021/07/01");
  script_set_attribute(attribute:"patch_publication_date", value:"2021/07/01");
  script_set_attribute(attribute:"plugin_publication_date", value:"2021/07/08");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:microsoft:windows");
  script_set_attribute(attribute:"stig_severity", value:"I");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Windows : Microsoft Bulletins");

  script_copyright(english:"This script is Copyright (C) 2021 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("smb_check_rollup.nasl", "smb_hotfixes.nasl", "ms_bulletin_checks_possible.nasl");
  script_require_keys("SMB/MS_Bulletin_Checks/Possible");
  script_require_ports(139, 445, "Host/patch_management_checks");

  exit(0);
}

include('smb_func.inc');
include('smb_hotfixes.inc');
include('smb_hotfixes_fcheck.inc');
include('smb_reg_query.inc');

get_kb_item_or_exit('SMB/MS_Bulletin_Checks/Possible');

bulletin = 'MS21-07';
kbs = make_list(
  '5004948'
);

if (get_kb_item('Host/patch_management_checks')) hotfix_check_3rd_party(bulletin:bulletin, kbs:kbs, severity:SECURITY_HOLE);

get_kb_item_or_exit('SMB/Registry/Enumerated');
get_kb_item_or_exit('SMB/WindowsVersion', exit_code:1);

if (hotfix_check_sp_range(win10:'0') <= 0) audit(AUDIT_OS_SP_NOT_VULN);

share = hotfix_get_systemdrive(as_share:TRUE, exit_on_fail:TRUE);
if (!is_accessible_share(share:share)) audit(AUDIT_SHARE_FAIL, share);

if (
  smb_check_rollup(os:'10', 
                   sp:0,
                   os_build:'14393',
                   rollup_date:'06_2021_07_01',
                   bulletin:bulletin,
                   rollup_kb_list:[5004948])
)
{
  replace_kb_item(name:'SMB/Missing/'+bulletin, value:TRUE);
  hotfix_security_hole();
  hotfix_check_fversion_end();
  exit(0);
}
else
{
  hotfix_check_fversion_end();
  audit(AUDIT_HOST_NOT, hotfix_get_audit_report());
}