Vulnerabilities > CVE-2019-1649 - Improper Locking vulnerability in Cisco products

047910
CVSS 6.7 - MEDIUM
Attack vector
LOCAL
Attack complexity
LOW
Privileges required
HIGH
Confidentiality impact
HIGH
Integrity impact
HIGH
Availability impact
HIGH
local
low complexity
cisco
CWE-667
nessus

Summary

A vulnerability in the logic that handles access control to one of the hardware components in Cisco's proprietary Secure Boot implementation could allow an authenticated, local attacker to write a modified firmware image to the component. This vulnerability affects multiple Cisco products that support hardware-based Secure Boot functionality. The vulnerability is due to an improper check on the area of code that manages on-premise updates to a Field Programmable Gate Array (FPGA) part of the Secure Boot hardware implementation. An attacker with elevated privileges and access to the underlying operating system that is running on the affected device could exploit this vulnerability by writing a modified firmware image to the FPGA. A successful exploit could either cause the device to become unusable (and require a hardware replacement) or allow tampering with the Secure Boot verification process, which under some circumstances may allow the attacker to install and boot a malicious software image. An attacker will need to fulfill all the following conditions to attempt to exploit this vulnerability: Have privileged administrative access to the device. Be able to access the underlying operating system running on the device; this can be achieved either by using a supported, documented mechanism or by exploiting another vulnerability that would provide an attacker with such access. Develop or have access to a platform-specific exploit. An attacker attempting to exploit this vulnerability across multiple affected platforms would need to research each one of those platforms and then develop a platform-specific exploit. Although the research process could be reused across different platforms, an exploit developed for a given hardware platform is unlikely to work on a different hardware platform.

Vulnerable Configurations

Part Description Count
OS
Cisco
7733
Hardware
Cisco
166

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Leveraging Race Conditions
    This attack targets a race condition occurring when multiple processes access and manipulate the same resource concurrently and the outcome of the execution depends on the particular order in which the access takes place. The attacker can leverage a race condition by "running the race", modifying the resource and modifying the normal execution flow. For instance a race condition can occur while accessing a file, the attacker can trick the system by replacing the original file with his version and cause the system to read the malicious file.
  • Leveraging Race Conditions via Symbolic Links
    This attack leverages the use of symbolic links (Symlinks) in order to write to sensitive files. An attacker can create a Symlink link to a target file not otherwise accessible to her. When the privileged program tries to create a temporary file with the same name as the Symlink link, it will actually write to the target file pointed to by the attackers' Symlink link. If the attacker can insert malicious content in the temporary file she will be writing to the sensitive file by using the Symlink. The race occurs because the system checks if the temporary file exists, then creates the file. The attacker would typically create the Symlink during the interval between the check and the creation of the temporary file.

Nessus

NASL familyCISCO
NASL idCISCO-SA-20190513-SECUREBOOT-FTD.NASL
descriptionAccording to its version, the Cisco Firepower Threat Defense (FTD) software installed on the remote host is affected by a vulnerability in the logic that handles access control to one of the hardware components in Cisco
last seen2020-04-30
modified2019-05-23
plugin id125341
published2019-05-23
reporterThis script is Copyright (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
sourcehttps://www.tenable.com/plugins/nessus/125341
titleCisco Firepower Threat Defense (FTD) Secure Boot Hardware Tampering Vulnerability (cisco-sa-20190513-secureboot)
code
#
# (C) Tenable Network Security, Inc.
#

include('compat.inc');

if (description)
{
  script_id(125341);
  script_version("1.5");
  script_set_attribute(attribute:"plugin_modification_date", value:"2020/04/27");

  script_cve_id("CVE-2019-1649");
  script_xref(name:"CISCO-BUG-ID", value:"CSCvn77248");
  script_xref(name:"CISCO-SA", value:"cisco-sa-20190513-secureboot");
  script_xref(name:"IAVA", value:"2019-A-0177");

  script_name(english:"Cisco Firepower Threat Defense (FTD) Secure Boot Hardware Tampering Vulnerability (cisco-sa-20190513-secureboot)");
  script_summary(english:"Checks the version of Cisco Firepower Threat Defense.");

  script_set_attribute(attribute:"synopsis", value:
"The remote device is missing a vendor-supplied security patch");
  script_set_attribute(attribute:"description", value:
"According to its version, the Cisco Firepower Threat Defense (FTD) software installed on the remote host is affected by
a vulnerability in the logic that handles access control to one of the hardware components in Cisco's proprietary Secure
Boot implementation could allow an authenticated, local attacker to write a modified firmware image to the component.
This vulnerability affects multiple Cisco products that support hardware-based Secure Boot functionality. The
vulnerability is due to an improper check on the area of code that manages on-premise updates to a Field Programmable
Gate Array (FPGA) part of the Secure Boot hardware implementation. An attacker with elevated privileges and access to
the underlying operating system that is running on the affected device could exploit this vulnerability by writing a
modified firmware image to the FPGA. A successful exploit could either cause the device to become unusable (and require
a hardware replacement) or allow tampering with the Secure Boot verification process, which under some circumstances may
allow the attacker to install and boot a malicious software image.

Please see the included Cisco BIDs and Cisco Security Advisory for more information");
  # https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190513-secureboot
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?e13bd4a7");
  script_set_attribute(attribute:"see_also", value:"https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvn77248");
  script_set_attribute(attribute:"solution", value:
"Upgrade to the relevant fixed version referenced in Cisco bug ID CSCvn77248");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:N/C:C/I:C/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:H/UI:N/S:U/C:H/I:H/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-2019-1649");
  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_cwe_id(284);

  script_set_attribute(attribute:"vuln_publication_date", value:"2019/05/13");
  script_set_attribute(attribute:"patch_publication_date", value:"2019/05/13");
  script_set_attribute(attribute:"plugin_publication_date", value:"2019/05/23");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe",value:"cpe:/a:cisco:firepower");
  script_set_attribute(attribute:"cpe",value:"cpe:/a:cisco:firepower_threat_defense");
  script_set_attribute(attribute:"stig_severity", value:"I");
  script_set_attribute(attribute:"potential_vulnerability", value:"true");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.");
  script_family(english:"CISCO");

  script_dependencies("ssh_get_info.nasl", "os_fingerprint.nasl", "cisco_asa_firepower_version.nasl", "cisco_enumerate_firepower.nbin");
  script_require_keys("installed_sw/Cisco Firepower Threat Defense", "Settings/ParanoidReport");
  exit(0);
}

include('vcf.inc');
include('audit.inc');
include('cisco_workarounds.inc');
include('ccf.inc');

if (report_paranoia < 2) audit(AUDIT_PARANOID);

app_info = vcf::get_app_info(app:'Cisco Firepower Threat Defense');
product_info = make_array('model' , app_info['Model'], 'version' , app_info['version'], 'name', 'Cisco Firepower Threat Defense');

vuln_ranges = [
  {'min_ver' : '6.4',  'fix_ver' : '6.4.0.1'},
  {'min_ver' : '6.3',  'fix_ver' : '6.3.0.3'},
  {'min_ver' : '6.2.3', 'fix_ver' : '6.2.3.12'},
  {'min_ver' : '0.0',  'fix_ver' : '6.2.2.5'}
];

workarounds = make_list(CISCO_WORKAROUNDS['no_workaround']);
workaround_params = make_list();

reporting = make_array(
  'port'     , 0,
  'severity' , SECURITY_HOLE,
  'version'  , product_info['version'],
  'bug_id'   , 'CSCvn77248'
);

cisco::check_and_report(
  product_info:product_info,
  workarounds:workarounds,
  workaround_params:workaround_params,
  reporting:reporting,
  vuln_ranges:vuln_ranges
);

The Hacker News

idTHN:105F9F5DCF89EE3373392069DE620906
last seen2019-05-14
modified2019-05-14
published2019-05-14
reporterThe Hacker News
sourcehttps://thehackernews.com/2019/05/cisco-secure-boot-bypass.html
titleFlaw Affecting Millions of Cisco Devices Let Attackers Implant Persistent Backdoor