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             AUSCERT External Security Bulletin Redistribution

                               ESB-2023.1726
         Cisco IOS XE Software Web UI Path Traversal Vulnerability
                               23 March 2023

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

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

Product:           Cisco IOS XE Software
Publisher:         Cisco Systems
Operating System:  Cisco
Resolution:        Patch/Upgrade
CVE Names:         CVE-2023-20066  

Original Bulletin: 
   https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-webui-pthtrv-es7GSb9V

Comment: CVSS (Max):  6.5 CVE-2023-20066 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N)
         CVSS Source: Cisco Systems
         Calculator:  https://www.first.org/cvss/calculator/3.1#CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

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Cisco IOS XE Software Web UI Path Traversal Vulnerability

Priority:        Medium
Advisory ID:     cisco-sa-webui-pthtrv-es7GSb9V
First Published: 2023 March 22 16:00 GMT
Version 1.0:     Final
Workarounds:     No workarounds available
Cisco Bug IDs:   CSCwc76009
CVE Names:       CVE-2023-20066

Summary

  o A vulnerability in the web UI of Cisco IOS XE Software could allow an
    authenticated, remote attacker to perform a directory traversal and access
    resources that are outside the filesystem mountpoint of the web UI.

    This vulnerability is due to an insufficient security configuration. An
    attacker could exploit this vulnerability by sending a crafted request to
    the web UI. A successful exploit could allow the attacker to gain read 
    access to files that are outside the filesystem mountpoint of the web UI.

    Note: These files are located on a restricted filesystem that is maintained
    for the web UI. There is no ability to write to any files on this
    filesystem.

    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://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-webui-pthtrv-es7GSb9V

    This advisory is part of the March 2023 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 2023
    Semiannual Cisco IOS and IOS XE Software Security Advisory Bundled
    Publication .

Affected Products

  o Vulnerable Products

    At the time of publication, this vulnerability affected Cisco IOS XE
    Software if it had the web UI enabled.

    For information about which Cisco software releases were vulnerable at the
    time of publication, 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, 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
       Meraki products
       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.

    While this mitigation has been deployed and was 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 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 . This tool
    identifies any Cisco security advisories that impact a specific software
    release and the earliest release that fixes the vulnerabilities that are
    described in each advisory ("First Fixed"). If applicable, the tool also
    returns the earliest release that fixes all the vulnerabilities that are
    described in all the advisories that the Software Checker identifies
    ("Combined First Fixed").

    To use the tool, go to the Cisco Software Checker page and follow the
    instructions. Alternatively, use the following form to determine whether a
    release is affected by any Cisco Security Advisory. To use the form, follow
    these steps:

     1. Choose which advisories the tool will search-only this advisory, only
        advisories with a Critical or High Security Impact Rating (SIR) , or
        all advisories.
     2. Enter a release number-for example, 15.9(3)M2 or 17.3.3.
     3. Click Check .


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 Cisco would like to thank Elias Ikkela-Koski for reporting this
    vulnerability.

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.

Subscribe to Cisco Security Notifications

  o Subscribe

Related to This Advisory

  o Cisco Event Response: March 2023 Semiannual Cisco IOS and IOS XE Software
    Security Advisory Bundled Publication

URL

  o https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-webui-pthtrv-es7GSb9V

Revision History

  o +----------+---------------------------+----------+--------+--------------+
    | Version  |        Description        | Section  | Status |     Date     |
    +----------+---------------------------+----------+--------+--------------+
    | 1.0      | Initial public release.   | -        | Final  | 2023-MAR-22  |
    +----------+---------------------------+----------+--------+--------------+

Legal Disclaimer

  o THIS DOCUMENT IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY KIND
    OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR
    FITNESS FOR A PARTICULAR USE. YOUR USE OF THE INFORMATION ON THE DOCUMENT
    OR MATERIALS LINKED FROM THE DOCUMENT IS AT YOUR OWN RISK. CISCO RESERVES
    THE RIGHT TO CHANGE OR UPDATE THIS DOCUMENT AT ANY TIME.

    A standalone copy or paraphrase of the text of this document that omits the
    distribution URL is an uncontrolled copy and may lack important information
    or contain factual errors. The information in this document is intended for
    end users of Cisco products.

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