Summary

• Multiple vulnerabilities in the web management framework of Cisco IOS XE Software could allow an authenticated, remote attacker with read-only privileges to gain unauthorized read access to sensitive data or cause the web management software to hang or crash, resulting in a denial of service (DoS) condition.

  For more information about these vulnerabilities, see the Details section of this advisory.

  Cisco has released software updates that address these vulnerabilities. There are no workarounds that address these vulnerabilities.

  This advisory is available at the following link:
  https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ios-xe-webui-multi-vfTkk7yr

Affected Products

• Vulnerable Products

  At the time of publication, these vulnerabilities affect Cisco devices if they are running a vulnerable release of Cisco IOS XE Software and have the HTTP server enabled. The default state of the HTTP Server feature in Cisco IOS XE Software is version 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 vulnerabilities are 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 vulnerabilities are 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 these vulnerabilities.

  Cisco has confirmed that these vulnerabilities do not affect the following Cisco products:

  • IOS Software
  • IOS XR Software
  • NX-OS Software

Details

• The vulnerabilities are not dependent on one another. Exploitation of one of the vulnerabilities is not required to exploit the other vulnerability. In addition, a software release that is affected by one of the vulnerabilities may not be affected by the other vulnerability.

  Details about the vulnerabilities are as follows.

  Cisco IOS XE Web Management Software Denial of Service Vulnerability

  A vulnerability in the web management framework of Cisco IOS XE Software could allow an authenticated, remote attacker with read-only privileges to cause a DoS condition on an affected device.

  The vulnerability is due to insufficient validation of user-supplied input. An attacker could exploit this vulnerability by sending crafted HTTP packets to an affected device. A successful exploit could allow the attacker to cause the web management software to hang or crash, resulting in a DoS condition and requiring that the device be restarted to regain functionality.

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

  Bug ID(s): CSCvs40364
  CVE ID: CVE-2020-3474
  Security Impact Rating (SIR): Medium
  CVSS Base Score: 4.3
  CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

  Cisco IOS XE Web Management Software Information Disclosure Vulnerability

  A vulnerability in the web management framework of Cisco IOS XE Software could allow an authenticated, remote attacker with read-only privileges to gain unauthorized access to sensitive information.

  The vulnerability is due to a lack of input and validation checking mechanisms for certain GET requests to APIs on an affected device. An attacker could exploit this vulnerability by sending HTTP GET requests to an affected device. A successful exploit could allow the attacker to gain unauthorized read access to sensitive data on the affected device.

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

  Bug ID(s): CSCvs40405
  CVE ID: CVE-2020-3475
  Security Impact Rating (SIR): Medium
  CVSS Base Score:4.3
  CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

Workarounds

• There are no workarounds that address these vulnerabilities.

  Disabling the HTTP Server feature eliminates the attack vector for these vulnerabilities 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

• 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:

  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

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

Source

• Cisco would like to thank Kwangho Park (panghoddari) of KITRI BoB for finding and reporting these vulnerabilities.

URL

• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ios-xe-webui-multi-vfTkk7yr

Revision History

• Version	Description	Section	Status	Date
  1.0	Initial public release.	-	Final	2020-SEP-24

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