Operating System:

[Cisco]

Published:

25 September 2020

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             AUSCERT External Security Bulletin Redistribution

                               ESB-2020.3274
               Cisco IOS XE Software Web UI vulnerabilities
                             25 September 2020

===========================================================================

        AusCERT Security Bulletin Summary
        ---------------------------------

Product:           Cisco IOS XE Software Web UI
Publisher:         Cisco Systems
Operating System:  Cisco
Impact/Access:     Denial of Service   -- Existing Account
                   Unauthorised Access -- Existing Account
Resolution:        Patch/Upgrade
CVE Names:         CVE-2020-3516 CVE-2020-3400 

Original Bulletin: 
   https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-webui-auth-bypass-6j2BYUc7
   https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-WEB-UI-exNFmcPO

Comment: This bulletin contains two (2) Cisco Systems security advisories.

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

Cisco IOS XE Software Web UI Authorization Bypass Vulnerability

Priority:        High

Advisory ID:     cisco-sa-webui-auth-bypass-6j2BYUc7

First Published: 2020 September 24 16:00 GMT

Version 1.0:     Final

Workarounds:     No workarounds available

Cisco Bug IDs:   CSCva31948

CVE-2020-3400    

CWE-862

CVSS Score:
8.8  AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:X/RL:X/RC:X

Summary

  o A vulnerability in the web UI feature of Cisco IOS XE Software could allow
    an authenticated, remote attacker to utilize parts of the web UI for which
    they are not authorized.

    The vulnerability is due to insufficient authorization of web UI access
    requests. An attacker could exploit this vulnerability by sending a crafted
    HTTP request to the web UI. A successful exploit could allow the attacker
    to utilize parts of the web UI for which they are not authorized. This
    could allow a Read-Only user to perform actions of an Admin user.

    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:
    https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/
    cisco-sa-webui-auth-bypass-6j2BYUc7

    This advisory is part of the September 24, 2020, release of the Cisco IOS
    and IOS XE Software Security Advisory Bundled Publication, which includes
    25 Cisco Security Advisories that describe 34 vulnerabilities. For a
    complete list of the advisories and links to them, see Cisco Event
    Response: September 2020 Semiannual Cisco IOS and IOS XE Software Security
    Advisory Bundled Publication .

Affected Products

  o Vulnerable Products

    This vulnerability affects Cisco devices that are running a vulnerable
    release of Cisco IOS XE Software with the HTTP Server feature enabled. The
    default state of the HTTP Server feature in Cisco IOS XE Software is
    platform dependent.

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

    Determine the HTTP Server Configuration

    To determine whether the HTTP Server feature is enabled for a device, log
    in to the device and use the show running-config | include ip http server|
    secure|active command in the CLI to check for the presence of the ip http
    server command or the ip http secure-server command in the global
    configuration. If either command is present and configured, the HTTP Server
    feature is enabled for the device.

    The following example shows the output of the show running-config | include
    ip http server|secure|active command for a device that has the HTTP Server
    feature enabled:

        Router# show running-config | include ip http server|secure|active
        ip http server
        ip http secure-server

    Note: The presence of either command or both commands in the device
    configuration indicates that the web UI feature is enabled.

    If the ip http server command is present and the configuration also
    contains ip http active-session-modules none , the vulnerability is not
    exploitable over HTTP.

    If the ip http secure-server command is present and the configuration also
    contains ip http secure-active-session-modules none , the vulnerability is
    not exploitable over HTTPS.

    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 Software
       IOS XR Software
       NX-OS Software

Workarounds

  o There are no workarounds that address this vulnerability.

    Disabling the HTTP Server feature eliminates the attack vector for this
    vulnerability and may be a suitable mitigation until affected devices can
    be upgraded. To disable the HTTP Server feature, use the no ip http server 
    or no ip http secure-server command in global configuration mode. If both
    the HTTP server and HTTPS server are in use, both commands are required to
    disable the HTTP Server feature.

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: https://www.cisco.com/c/en/us/products/
    end-user-license-agreement.html

    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 and Alerts 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
    providers.

    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
    /en/us/support/web/tsd-cisco-worldwide-contacts.html

    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
    upgrade.

    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 :

    [                    ] [Check]

    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.

Source

  o This vulnerability was found during internal security testing.

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: September 2020 Semiannual Cisco IOS and IOS XE
    Software Security Advisory Bundled Publication

URL

  o https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/
    cisco-sa-webui-auth-bypass-6j2BYUc7

Revision History

  o +----------+---------------------------+----------+--------+--------------+
    | Version  |        Description        | Section  | Status |     Date     |
    +----------+---------------------------+----------+--------+--------------+
    | 1.0      | Initial public release.   | -        | Final  | 2020-SEP-24  |
    +----------+---------------------------+----------+--------+--------------+

- --------------------------------------------------------------------------------

Cisco IOS XE Software Web UI Improper Input Validation Vulnerability

Priority:        Medium

Advisory ID:     cisco-sa-WEB-UI-exNFmcPO

First Published: 2020 September 24 16:00 GMT

Version 1.0:     Final

Workarounds:     No workarounds available

Cisco Bug IDs:   CSCvr73955

CVE-2020-3516    

CWE-20

CVSS Score:
4.3  AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:X/RL:X/RC:X

Summary

  o A vulnerability in the web server authentication of Cisco IOS XE Software
    could allow an authenticated, remote attacker to crash the web server on
    the device.

    The vulnerability is due to insufficient input validation during
    authentication. An attacker could exploit this vulnerability by entering
    unexpected characters during a valid authentication. A successful exploit
    could allow the attacker to crash the web server on the device, which must
    be manually recovered by disabling and re-enabling the web server.

    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:
    https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/
    cisco-sa-WEB-UI-exNFmcPO

Affected Products

  o Vulnerable Products

    At the time of publication, this vulnerability affected Cisco IOS XE
    Software releases earlier than releases 16.9.6, 16.12.2, or 17.1.1.

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

    Determine the HTTP Server Configuration

    To determine whether the HTTP Server feature is enabled for a device, log
    in to the device and use the show running-config | include ip http server|
    secure|active command in the CLI to check for the presence of the ip http
    server command or the ip http secure-server command in the global
    configuration. If either command is present and configured, the HTTP Server
    feature is enabled for the device.

    The following example shows the output of the show running-config | include
    ip http server|secure|active command for a device that has the HTTP Server
    feature enabled:

        Router# show running-config | include ip http server|secure|active
        ip http server
        ip http secure-server

    Note: The presence of either command or both commands in the device
    configuration indicates that the web UI feature is enabled.

    If the ip http server command is present and the configuration also
    contains ip http active-session-modules none , the vulnerability is not
    exploitable over HTTP.

    If the ip http secure-server command is present and the configuration also
    contains ip http secure-active-session-modules none , the vulnerability is
    not exploitable over HTTPS.

    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 Software
       IOS XR Software
       NX-OS Software

Details

  o When this vulnerability is exploited, only the web server functionality is
    broken. General traffic through the device is unaffected.

Workarounds

  o There are no workarounds that address this vulnerability.

    Disabling the HTTP Server feature eliminates the attack vector for this
    vulnerability and may be a suitable mitigation until affected devices can
    be upgraded. To disable the HTTP Server feature, use the no ip http server 
    or no ip http secure-server command in global configuration mode. If both
    the HTTP server and HTTPS server are in use, both commands are required to
    disable the HTTP Server feature.

Fixed Software

  o 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
    providers.

    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 :

    [                    ] [Check]

    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.

Source

  o This vulnerability was found during internal security testing.

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.

URL

  o https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/
    cisco-sa-WEB-UI-exNFmcPO

Revision History

  o +----------+---------------------------+----------+--------+--------------+
    | Version  |        Description        | Section  | Status |     Date     |
    +----------+---------------------------+----------+--------+--------------+
    | 1.0      | Initial public release.   | -        | Final  | 2020-SEP-23  |
    +----------+---------------------------+----------+--------+--------------+

- --------------------------END INCLUDED TEXT--------------------

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