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AUSCERT External Security Bulletin Redistribution
Cisco IOS XE Software Web UI Cross-Site Request Forgery Vulnerability
17 July 2019
AusCERT Security Bulletin Summary
Product: Cisco IOS XE Software Web UI
Publisher: Cisco Systems
Operating System: Cisco
Impact/Access: Cross-site Request Forgery -- Remote with User Interaction
CVE Names: CVE-2019-1904
Revision History: July 17 2019: Updated Determining the HTTP Server Configuration section in Vulnerable Products
June 13 2019: Initial Release
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Cisco IOS XE Software Web UI Cross-Site Request Forgery Vulnerability
Advisory ID: cisco-sa-20190612-iosxe-csrf
First Published: 2019 June 12 16:00 GMT
Last Updated: 2019 July 16 15:51 GMT
Version 1.1: Final
Workarounds: No workarounds availableCisco Bug IDs: CSCuy98103
o A vulnerability in the web-based UI (web UI) of Cisco IOS XE Software could
allow an unauthenticated, remote attacker to conduct a cross-site request
forgery (CSRF) attack on an affected system.
The vulnerability is due to insufficient CSRF protections for the web UI on
an affected device. An attacker could exploit this vulnerability by
persuading a user of the interface to follow a malicious link. A successful
exploit could allow the attacker to perform arbitrary actions with the
privilege level of the affected user. If the user has administrative
privileges, the attacker could alter the configuration, execute commands,
or reload an affected 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:
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 is version dependent.
For information about which Cisco IOS XE Software releases are vulnerable,
see the Fixed Software section of this advisory.
Determining the HTTP Server Configuration
To determine whether the HTTP Server feature is enabled for a device,
administrators can log in to the device and use the show running-config |
include ip http server|secure-server 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-server command for a device that has the HTTP Server
Router# show running-config | include ip http server|secure-server
ip http server
ip http secure-server
The presence of either command in the device configuration indicates that
the HTTP Server feature is enabled.
If the output from the previous command also contains:
ip http active-session-modules none
ip http secure-active-session-modules none
The device is not affected by the vulnerability described in this advisory.
Determining the Cisco IOS XE Software Release
To determine which Cisco IOS XE Software release is running on a device,
administrators can log in to the device, use the show version command in
the CLI, and then refer to the system banner that appears. If the device is
running Cisco IOS XE Software, the system banner displays Cisco IOS
Software , Cisco IOS XE Software , or similar text.
The following example shows the output of the command for a device that is
running Cisco IOS XE Software Release 16.2.1 and has an installed image
name of CAT3K_CAA-UNIVERSALK9-M :
ios-xe-device# show version
Cisco IOS Software, Catalyst L3 Switch Software (CAT3K_CAA-UNIVERSALK9-M), Version Denali 16.2.1, RELEASE SOFTWARE (fc1)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2016 by Cisco Systems, Inc.
Compiled Sun 27-Mar-16 21:47 by mcpre
For information about the naming and numbering conventions for Cisco IOS XE
Software releases, see the Cisco IOS and NX-OS Software Reference Guide .
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 Cisco IOS
Software, Cisco IOS XR Software, or Cisco NX-OS Software.
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. Administrators can disable the HTTP Server feature by using
the no ip http server or no ip http secure-server command in global
configuration mode. If both http server and http-secure server are in use,
then both commands are required to disable the HTTP Server feature.
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
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
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:
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 a tool, the Cisco IOS Software Checker
, that identifies 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 this tool to perform the following tasks:
Initiate a search by choosing one or more releases from a drop-down
list or uploading a file from a local system for the tool to parse
Enter the output of the show version command for the tool to parse
Create a custom search by including all previously published Cisco
Security Advisories, a specific advisory, or all advisories in the most
recent bundled publication
To determine whether a release is affected by any published Cisco Security
Advisory, use the Cisco IOS Software Checker on Cisco.com or enter a Cisco
IOS or IOS XE Software release-for example, 15.1(4)M2 or 3.13.8S -in the
[ ] [Check]
By default, the Cisco IOS Software Checker includes results only for
vulnerabilities that have a Critical or High Security Impact Rating (SIR).
To include results for Medium SIR vulnerabilities, use the Cisco IOS
Software Checker on Cisco.com and check the Medium check box in the Impact
Rating drop-down list.
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.
Note: Starting with Cisco IOS XE Software Release 16.9.1, any upgrade will
require Smart Licensing. Customers who plan to upgrade Cisco IOS XE to
Release 16.9.1 or later are advised to consider the Smart Licensing
requirement. The following documentation provides additional information:
Smart Licensing .
Exploitation and Public Announcements
o The Cisco Product Security Incident Response Team (PSIRT) is aware of the
existence of exploit code that demonstrates this vulnerability on Cisco IOS
XE Software. There are no indications at this time that this exploit code
is publicly available.
Cisco PSIRT is not aware of any malicious use of the vulnerability that is
described in this advisory.
o This vulnerability was found during internal security testing.
This vulnerability was also independently discovered by Mr. James Chambers
(Research Scientist) of Red Balloon Security. Cisco would like to thank Red
Balloon Security for reporting this vulnerability to Cisco and working
toward a coordinated disclosure.
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.
Action Links for This Advisory
o Snort Rule 50427
| Version | Description | Section | Status | Date |
| | Updated Determining the | | | |
| 1.1 | HTTP Server | Vulnerable | Final | 2019-July-16 |
| | Configuration section in | Products | | |
| | Vulnerable Products. | | | |
| 1.0 | Initial public release. | - | Final | 2019-June-12 |
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