# ICS Advisory (ICSA-18-107-05)
## Rockwell Automation Stratix Industrial Managed Ethernet Switch
Original release date: April 17, 2018 | Last revised: April 25, 2018
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* * *
## 1\. EXECUTIVE SUMMARY
* **CVSS v3 9.8**
* **ATTENTION** : Exploitable remotely/low skill level to exploit.
* **Vendor** : Rockwell Automation
* **Equipment** : Allen-Bradley Stratix Industrial Managed Ethernet Switch
* **Vulnerabilities** : Improper Input Validation, Resource Management Errors, 7PK - Errors, Improper Restriction of Operations within the Bounds of a Memory Buffer, Use of Externally-Controlled Format String.
## 2\. RISK EVALUATION
Successful exploitation of these vulnerabilities could result in loss of
availability, confidentiality, and/or integrity caused by memory exhaustion,
module restart, information corruption, and/or information exposure.
## 3\. TECHNICAL DETAILS
### 3.1 AFFECTED PRODUCTS
The following versions of Allen-Bradley Stratix Industrial Managed Ethernet
Switch use a vulnerable version of Cisco IOS or IOS XE:
* Allen-Bradley Stratix 8300 Industrial Managed Ethernet Switches, versions 15.2(4a)EA5 and earlier.
### 3.2 VULNERABILITY OVERVIEW
### 3.2.1 [IMPROPER INPUT VALIDATION
CWE-20](https://cwe.mitre.org/data/definitions/20.html)
A vulnerability in the Smart Install feature of Cisco IOS Software and Cisco
IOS XE Software could allow an unauthenticated remote attacker to trigger a
reload of an affected device, resulting in a denial of service (DoS)
condition, or to execute arbitrary code on an affected device.
The vulnerability is due to improper validation of packet data. An attacker
could exploit this vulnerability by sending a crafted Smart Install message to
an affected device on TCP port 4786. A successful exploit could allow the
attacker to cause a buffer overflow on the affected device.
[CVE-2018-0171](http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2018-0171)
has been assigned to this vulnerability. A CVSS v3 base score of 9.8 has been
calculated; the CVSS vector string is
([AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H](https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)).
### 3.2.2 [RESOURCE MANAGEMENT ERRORS
CWE-399](https://cwe.mitre.org/data/definitions/399.html)
A vulnerability in the Smart Install feature of Cisco IOS Software and Cisco
IOS XE Software could allow an unauthenticated remote attacker to trigger a
reload of an affected device, resulting in a DoS condition.
The vulnerability is due to improper validation of packet data. An attacker
could exploit this vulnerability by sending a crafted packet to an affected
device on TCP port 4786.
[CVE-2018-0156](http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2018-0156)
has been assigned to this vulnerability. A CVSS v3 base score of 8.6 has been
assigned; the CVSS vector string is
([AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H](https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H)).
### 3.2.3 [7PK - ERRORS
CWE-388](https://cwe.mitre.org/data/definitions/388.html)
A vulnerability in the Bidirectional Forwarding Detection (BFD) offload
implementation could allow an unauthenticated remote attacker to cause a crash
of the iosd process, causing a DoS condition.
The vulnerability is due to insufficient error handling when the BFD header in
a BFD packet is incomplete. An attacker could exploit this vulnerability by
sending a crafted BFD message to or across an affected switch. A successful
exploit could allow the attacker to trigger a reload of the system.
[CVE-2018-0155](http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2018-0155)
has been assigned to this vulnerability. A CVSS v3 base score of 8.6 has been
calculated; the CVSS vector string is
([AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H](https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H)).
### 3.2.4 [IMPROPER INPUT VALIDATION
CWE-20](https://cwe.mitre.org/data/definitions/20.html)
A vulnerability in the DHCP option 82 encapsulation functionality of Cisco IOS
Software and Cisco IOS XE Software could allow an unauthenticated remote
attacker to cause an affected device to reload, resulting in a DoS condition.
The vulnerability exists because the affected software performs incomplete
input validation of option 82 information that it receives in DHCP Version 4
(DHCPv4) packets from DHCP relay agents. An attacker could exploit this
vulnerability by sending a crafted DHCPv4 packet to an affected device. A
successful exploit could allow the attacker to cause the affected device to
reload, resulting in a DoS condition.
[CVE-2018-0174](http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2018-0174)
has been assigned to this vulnerability. A CVSS v3 base score of 8.6 has been
calculated; the CVSS vector string is
([AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H](https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H)).
### 3.2.5 [IMPROPER INPUT VALIDATION
CWE-20](https://cwe.mitre.org/data/definitions/20.html)
A vulnerability in the DHCP option 82 encapsulation functionality of Cisco IOS
Software and Cisco IOS XE Software could allow an unauthenticated remote
attacker to cause an affected device to reload, resulting in a DoS condition.
The vulnerability exists because the affected software performs incomplete
input validation of option 82 information that it receives in DHCP Version 4
(DHCPv4) packets from DHCP relay agents. An attacker could exploit this
vulnerability by sending a crafted DHCPv4 packet to an affected device. A
successful exploit could allow the attacker to cause a heap overflow condition
on the affected device, which will cause the device to reload and result in a
DoS condition.
[CVE-2018-0172](http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2018-0172)
has been assigned to this vulnerability. A CVSS v3 base score of 8.6 has been
calculated; the CVSS vector string is
([AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H](https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H)).
### 3.2.6 [IMPROPER INPUT VALIDATION
CWE-20](https://cwe.mitre.org/data/definitions/20.html)
A vulnerability in the Cisco IOS Software and Cisco IOS XE Software function
that restores encapsulated option 82 information in DHCP Version 4 (DHCPv4)
packets could allow an unauthenticated remote attacker to cause an affected
device to reload, resulting in a DoS condition.
The vulnerability exists because the affected software performs incomplete
input validation of encapsulated option 82 information that it receives in
DHCPOFFER messages from DHCPv4 servers. An attacker could exploit this
vulnerability by sending a crafted DHCPv4 packet to an affected device, which
the device would then forward to a DHCPv4 server. When the affected software
processes the option 82 information that is encapsulated in the response from
the server, an error could occur. A successful exploit could allow the
attacker to cause the affected device to reload, resulting in a DoS condition.
[CVE-2018-0173](http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2018-0173)
has been assigned to this vulnerability. A CVSS v3 base score of 8.6 has been
calculated; the CVSS vector string is
([AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H](https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H)).
### 3.2.7 [IMPROPER RESTRICTION OF OPERATIONS WITHIN THE BOUNDS OF A MEMORY
BUFFER CWE-119](https://cwe.mitre.org/data/definitions/119.html)
A buffer overflow vulnerability in the LLDP subsystem of Cisco IOS Software,
Cisco IOS XE Software, and Cisco IOS XR Software could allow an adjacent,
unauthenticated attacker to cause a DoS condition or execute arbitrary code
with elevated privileges.
[CVE-2018-0167](http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2018-0167)
has been assigned to this vulnerability. A CVSS v3 base score of 8.8 has been
calculated; the CVSS vector string is
([AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H](https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)).
### 3.2.8 [USE OF EXTERNALLY-CONTROLLED FORMAT STRING
CWE-134](https://cwe.mitre.org/data/definitions/134.html)
A format string vulnerability in the LLDP subsystem of Cisco IOS Software and
Cisco IOS XE Software could allow an adjacent, unauthenticated attacker to
cause a DoS condition or execute arbitrary code with elevated privileges.
[CVE-2018-0175](http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2018-0175)
has been assigned to this vulnerability. A CVSS v3 base score of 8.8 has been
calculated; the CVSS vector string is
([AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H](https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)).
### 3.3 BACKGROUND
* **Critical Infrastructure Sectors:** Critical Manufacturing, Energy, Water and Wastewater Systems
* **Countries/Areas Deployed:** Worldwide
* **Company Headquarters Location:** Wisconsin, USA
### 3.4 RESEARCHER
Rockwell Automation reported these vulnerabilities to NCCIC from the semi-
annual Cisco IOS and IOS XE Software Security Advisory Bundled Publication.
## 4\. MITIGATIONS
Rockwell Automation has released the following knowledge base article 1073315:
<https://rockwellautomation.custhelp.com/app/answers/detail/a_id/1073315/>
(login required)
Cisco has released new Snort Rules at
<https://www.cisco.com/web/software/286271056/117258/sf-
rules-2018-03-29-new.html> to help address the following vulnerabilities:
* CVE-2018-0171 - Snort Rule 46096 and 46097
* CVE-2018-0156 - Snort Rule 41725
* CVE-2018-0174 - Snort Rule 46120
* CVE-2018-0172 - Snort Rule 46104
* CVE-2018-0173 - Snort Rule 46119
Cisco adds the following notes for the Smart Install vulnerabilities
(CVE-2018-0171 and CVE-2018-0156):
* Smart Install is turned off by express setup; however, upgraded switches but not re-setup may have it enabled.
* Disable the Smart Install feature with the no vstack configuration command if it is not needed or once setup is complete.
* Users who do use the feature--and need to leave it enabled--can use ACLs to block incoming traffic on TCP port 4786.
CVE-2018-0155: Administrators who do not use the BFD feature in their
environments can disable the BFD feature by using the feature bfd disable
command in global configuration mode to prevent exploitation of this
vulnerability. Administrators who do use the BFD feature can implement Control
Plane Policing (CoPP) to allow processing of BFD packets from known BFD peers
only and drop all other BFD traffic to limit exposure.
CVE-2018-0167 and CVE-2018-0175 have no specific mitigations in place. See the
following Cisco advisory for more details:
<https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-
sa-20180328-lldp>
Rockwell Automation also recommends that users implement the following general
security guidelines:
* Help minimize network exposure for all control system devices and/or systems, and confirm that they are not accessible from the Internet.
* Locate control system networks and devices behind firewalls, and isolate them from the business network.
* When remote access is required, use secure methods, such as Virtual Private Networks (VPNs), recognizing that VPNs may have vulnerabilities and should be updated to the most current version available. Also recognize that VPN is only as secure as the connected devices.
NCCIC reminds organizations to perform proper impact analysis and risk
assessment prior to deploying defensive measures.
NCCIC also provides a section for [control systems security recommended
practices](/ics/content/recommended-practices) on the ICS-CERT web page.
Several recommended practices are available for reading and download,
including[ Improving Industrial Control Systems Cybersecurity with Defense-in-
Depth Strategies](/sites/default/files/recommended_practices/NCCIC_ICS-
CERT_Defense_in_Depth_2016_S508C.pdf).
Additional mitigation guidance and recommended practices are publicly
available in the ICS-CERT Technical Information Paper, [ICS-TIP-12-146-01B--
Targeted Cyber Intrusion Detection and Mitigation Strategies](/ics/tips/ICS-
TIP-12-146-01B), that is available for download from the [ICS-CERT
website.](/ics/)
Organizations observing any suspected malicious activity should follow their
established internal procedures and report their findings to NCCIC for
tracking and correlation against other incidents.
No known public exploits specifically target these vulnerabilities.
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