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             AUSCERT External Security Bulletin Redistribution

         Cisco IOS  and IOS XE Software Common Industrial Protocol
                    Privilege Escalation Vulnerability
                               25 March 2021


        AusCERT Security Bulletin Summary

Product:           Cisco IOS Software Common Industrial Protocol
                   Cisco IOS XE Software Common Industrial Protocol
Publisher:         Cisco Systems
Operating System:  Cisco
Impact/Access:     Administrator Compromise -- Existing Account
Resolution:        Patch/Upgrade
CVE Names:         CVE-2021-1392  

Original Bulletin: 

- --------------------------BEGIN INCLUDED TEXT--------------------

Cisco IOS  and IOS XE Software Common Industrial Protocol Privilege Escalation

Priority:        High
Advisory ID:     cisco-sa-XE-SAP-OPLbze68
First Published: 2021 March 24 16:00 GMT
Version 1.0:     Final
Workarounds:     No workarounds available
Cisco Bug IDs:   CSCvu58224
CVE Names:       CVE-2021-1392
CWEs:            CWE-522


  o A vulnerability in the CLI command permissions of Cisco IOS and Cisco IOS
    XE Software could allow an authenticated, local attacker to retrieve the
    password for Common Industrial Protocol (CIP) and then remotely configure
    the device as an administrative user.

    This vulnerability exists because incorrect permissions are associated with
    the show cip security CLI command. An attacker could exploit this
    vulnerability by issuing the command to retrieve the password for CIP on an
    affected device. A successful exploit could allow the attacker to
    reconfigure the device.

    Cisco has released software updates that address this vulnerability. There
    are no workarounds that address this vulnerability.

    This advisory is available at the following link:

    This advisory is part of the March 2021 release of the Cisco IOS and IOS XE
    Software Security Advisory Bundled Publication. For a complete list of the
    advisories and links to them, see Cisco Event Response: March 2021
    Semiannual Cisco IOS and IOS XE Software Security Advisory Bundled
    Publication .

Affected Products

  o Vulnerable Products

    This vulnerability affects Cisco devices if they are running a vulnerable
    release of Cisco IOS or Cisco IOS XE Software and have CIP enabled.

    CIP is not enabled by default.

    For information about which Cisco software releases are vulnerable, see the
    Fixed Software section of this advisory.

    Determine Whether CIP Is Enabled

    To determine whether CIP is enabled on a device, issue the show cip status 
    command and check the State: value . The following example shows that CIP
    is enabled for VLAN 1:

        Router> show cip status
        State : Enabled
        Vlan : 1

    If the command returns no output or returns an error message, as shown in
    the following example, the device is not affected by this vulnerability:

        Router> show cip status
        % Invalid input detected at '^' marker.

    Products Confirmed Not Vulnerable

    Only products listed in the Vulnerable Products section of this advisory
    are known to be affected by this vulnerability.

    Cisco has confirmed that this vulnerability does not affect the following
    Cisco products:

       IOS XR Software
       NX-OS Software


  o There are no workarounds that address this vulnerability. However,
    mitigations are available:

       Disabling the CIP feature eliminates the attack vector for this
        vulnerability and may be a suitable mitigation until affected devices
        can be upgraded. To disable the CIP feature, use the no cip enable 
        command in the interface configuration mode for the VLAN that CIP is
        currently enabled on.
       For devices that are configured with TACACS+ authentication,
        authorization, and accounting (AAA) command authorization, use this
        feature to give non-administrative users access to the commands that
        they require and deny access to all other commands.

    While these mitigations have been deployed and were proven successful in a
    test environment, customers should determine the applicability and
    effectiveness in their own environment and under their own use conditions.
    Customers should be aware that any workaround or mitigation that is
    implemented may negatively impact the functionality or performance of their
    network based on intrinsic customer deployment scenarios and limitations.
    Customers should not deploy any workarounds or mitigations before first
    evaluating the applicability to their own environment and any impact to
    such environment.

Fixed Software

  o Cisco has released free software updates that address the vulnerability
    described in this advisory. Customers may only install and expect support
    for software versions and feature sets for which they have purchased a
    license. By installing, downloading, accessing, or otherwise using such
    software upgrades, customers agree to follow the terms of the Cisco
    software license:

    Additionally, customers may only download software for which they have a
    valid license, procured from Cisco directly, or through a Cisco authorized
    reseller or partner. In most cases this will be a maintenance upgrade to
    software that was previously purchased. Free security software updates do
    not entitle customers to a new software license, additional software
    feature sets, or major revision upgrades.

    When considering software upgrades , customers are advised to regularly
    consult the advisories for Cisco products, which are available from the
    Cisco Security Advisories page , to determine exposure and a complete
    upgrade solution.

    In all cases, customers should ensure that the devices to be upgraded
    contain sufficient memory and confirm that current hardware and software
    configurations will continue to be supported properly by the new release.
    If the information is not clear, customers are advised to contact the Cisco
    Technical Assistance Center (TAC) or their contracted maintenance

    Customers Without Service Contracts

    Customers who purchase directly from Cisco but do not hold a Cisco service
    contract and customers who make purchases through third-party vendors but
    are unsuccessful in obtaining fixed software through their point of sale
    should obtain upgrades by contacting the Cisco TAC: https://www.cisco.com/c

    Customers should have the product serial number available and be prepared
    to provide the URL of this advisory as evidence of entitlement to a free

    Cisco IOS and IOS XE Software

    To help customers determine their exposure to vulnerabilities in Cisco IOS
    and IOS XE Software, Cisco provides the Cisco Software Checker to identify
    any Cisco Security Advisories that impact a specific software release and
    the earliest release that fixes the vulnerabilities described in each
    advisory ("First Fixed"). If applicable, the tool also returns the earliest
    release that fixes all the vulnerabilities described in all the advisories
    identified ("Combined First Fixed").

    Customers can use the Cisco Software Checker to search advisories in the
    following ways:

       Choose the software and one or more releases
       Upload a .txt file that includes a list of specific releases
       Enter the output of the show version command

    After initiating a search, customers can customize the search to include
    all Cisco Security Advisories, a specific advisory, or all advisories in
    the most recent bundled publication.

    Customers can also use the following form to determine whether a release is
    affected by any Cisco Security Advisory by entering a Cisco IOS or IOS XE
    Software release-for example, 15.1(4)M2 or 3.13.8S.

    By default, the Cisco Software Checker includes results only for
    vulnerabilities that have a Critical or High Security Impact Rating (SIR).
    To include results for Medium SIR vulnerabilities, customers can use the
    Cisco Software Checker on Cisco.com and check the Medium check box in the
    drop-down list under Impact Rating when customizing a search.

    For a mapping of Cisco IOS XE Software releases to Cisco IOS Software
    releases, refer to the Cisco IOS XE 2 Release Notes , Cisco IOS XE 3S
    Release Notes , or Cisco IOS XE 3SG Release Notes , depending on the Cisco
    IOS XE Software release.

Exploitation and Public Announcements

  o The Cisco Product Security Incident Response Team (PSIRT) is not aware of
    any public announcements or malicious use of the vulnerability that is
    described in this advisory.


  o This vulnerability was found during internal security testing by X.B. of
    the Cisco Advanced Security Initiatives Group (ASIG).

Cisco Security Vulnerability Policy

  o To learn about Cisco security vulnerability disclosure policies and
    publications, see the Security Vulnerability Policy . This document also
    contains instructions for obtaining fixed software and receiving security
    vulnerability information from Cisco.

Related to This Advisory

  o Cisco Event Response: March 2021 Semiannual Cisco IOS and IOS XE Software
    Security Advisory Bundled Publication


  o https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-XE-SAP-OPLbze68

Revision History

  o +----------+---------------------------+----------+--------+--------------+
    | Version  |        Description        | Section  | Status |     Date     |
    | 1.0      | Initial public release.   | -        | Final  | 2021-MAR-24  |

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