A vulnerability in the implementation of Security Assertion Markup Language (SAML) Single Sign-On (SSO) authentication for Cisco AnyConnect Secure Mobility Client for Desktop Platforms, Cisco Adaptive Security Appliance (ASA) Software, and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to establish an authenticated AnyConnect session through an affected device running ASA or FTD Software. The authentication would need to be done by an unsuspecting third party. The vulnerability exists because there is no mechanism for the ASA or FTD Software to detect that the authentication request originates from the AnyConnect client directly. An attacker could exploit this vulnerability by persuading a user to click a crafted link and authenticating using the company's Identity Provider (IdP). A successful exploit could allow the attacker to hijack a valid authentication token and use that to establish an authenticated AnyConnect session through an affected device running ASA or FTD Software. 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-20180418-asaanyconnect
ASA Software
The ASA Software is only vulnerable if running software version 9.7.1 or later.
Vulmon
ciscoasa# show version | include Version
Cisco Adaptive Security Appliance Software Version 9.7(1)4
Firepower Extensible Operating System Version 2.1(1.66)
Baseboard Management Controller (revision 0x1) Firmware Version: 2.4
Customers who use Cisco Adaptive Security Device Manager (ASDM) to manage devices can locate the software release in the table that appears in the login window or the upper-left corner of the Cisco ASDM window.
FTD Software
The FTD Software is only vulnerable if running software version 6.2.1 or later.
To determine which Cisco FTD Software release is running on a device, administrators can log in to the device and use the show version command in the CLI. The following example shows the output of the command for a device that is running Cisco FTD Software Release 6.2.2:
> show version
------------------[ ftd ]-----------------------
Model : Cisco Firepower 2130 Threat Defense (77) Version 6.2.2 (Build 81)
UUID : 0cd3595a-7efa-11e7-aaa1-ee3989c8bf25
Rules update version : 2017-12-20-001-vrt
VDB version : 290
----------------------------------------------------
AnyConnect Software
The AnyConnect Secure Mobility Client Software is only vulnerable if running software version 4.4.00243 or later.
ASA and FTD Features
The ASA software and the FTD software are vulnerable only if all of the following features are configured:
Note: SAML 2.0 for AnyConnect features are first supported as of ASA release 9.7.1, FTD release 6.2.1, and AnyConnect Secure Mobility Client release 4.4.00243.
To determine whether ASA or FTD is configured with a SAML 2.0 IdP, administrators can use the show webvpn saml idp CLI command. The following output shows an ASA configured with a SAML 2.0 IdP:
ciscoasa# show webvpn saml idp
saml idp my_domain_idp
url sign-in https://asa-dev.my.domain.com/idp/endpoint/HttpRedirect
url sign-out https://asa-dev.my.domain.com/idp/endpoint/HttpRedirect
trustpoint idp my_domain_trustpoint
trustpoint sp asa_trustpoint
To determine whether ASA or FTD is configured as SAML 2.0 SP, administrators can use the show running-config tunnel-group | include remote-access|webvpn-attributes|saml CLI command. The following output shows an ASA configured as SAML 2.0 SP:
ciscoasa# show running-config tunnel-group | include remote-access|webvpn-attributes|saml
tunnel-group cloud_idp_onelogin type remote-access
tunnel-group cloud_idp_onelogin webvpn-attributes
authentication saml
saml identity-provider my_domain_idp
To determine whether ASA or FTD is configured for AnyConnect Remote Access VPN, administrators can use the show running-config CLI command and consult the following table for vulnerable configurations.
| Feature | Vulnerable Configuration |
|---|---|
| AnyConnect IKEv2 Remote Access (with client services) |
crypto ikev2 enable webvpn anyconnect enable |
| AnyConnect IKEv2 Remote Access (without client services) |
crypto ikev2 enable webvpn anyconnect enable |
| AnyConnect SSL VPN |
webvpn enable |
The vulnerability described in this advisory originates from the dilemma that the head-end device that has the SAML 2.0-based SSO for AnyConnect feature enabled has no way to verify that the authentication request came from the same machine that is running the AnyConnect Secure Mobility Client.
The fix for this vulnerability involves changes in both the head-end device's ASA software and the client-side's AnyConnect Secure Mobility Client. This includes embedded browser functionality in the AnyConnect Secure Mobility Client. For a complete fix, both the head-end device and the AnyConnect Secure Mobility Client must be upgraded.
As the fix for this vulnerability requires protocol adjustments, the ASA has no automatic backward compatibility between the behavior of a solution running software versions prior to the fix and the default behavior of solutions running software versions that do include the fix.
For a transition period, both the AnyConnect Secure Mobility Client and ASA Software will support both methods. The AnyConnect Secure Mobility Client will automatically detect the correct behavior when talking to a head-end device. On the ASA side, the previous behavior will be disabled by default. The previous behavior can be enabled manually per Connection Profile ("tunnel-group") using the newly introduced saml external-browser command under webvpn-attributes.
When upgrading an ASA that has the SAML 2.0-based SSO for AnyConnect feature enabled, the new behavior will be enforced after the upgrade. Customers who cannot upgrade their AnyConnect clients at the same time will need to re-enable the previous behavior manually by adding the saml external-browser command after the ASA upgrade has completed. Cisco recommends removing the saml external-browser command after all AnyConnect clients have been migrated.
Please refer to the Important Notes section in the Release Notes for the Cisco ASA Series, 9.9(x), the About SSO and SAML 2.0 section in the Cisco ASA Series VPN CLI Configuration Guide, 9.9, the AnyConnect 4.6.00362 New Features section in the Release Notes for Cisco AnyConnect Secure Mobility Client, Release 4.6, and the VPN Authentication Using SAML section in the Cisco AnyConnect Secure Mobility Client Administrator Guide, Release 4.6 for further information on the changed behavior.
There are no workarounds that address this vulnerability.
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.
Note: For a complete fix, both the ASA or FTD Software on the head-end device and the AnyConnect Secure Mobility Client must be upgraded.
| Cisco ASA Major Release |
First Fixed Release for This Vulnerability |
Recommended Fixed Release for All the Vulnerabilities Described in this Collection of Advisories |
|---|---|---|
| Prior to 9.11 |
Not vulnerable2 | 9.1.7.20 |
| 9.1 | Not vulnerable2 | 9.1.7.20 |
| 9.2 | Not vulnerable2 |
9.2.4.27 |
| 9.31 | Not vulnerable2 |
9.4.4.14 |
| 9.4 | Not vulnerable2 |
9.4.4.14 |
| 9.51 | Not vulnerable2 |
9.6.4.6 |
| 9.6 | Not vulnerable2 |
9.6.4.6 |
| 9.7 | 9.7.1.24 | 9.7.1.24 |
| 9.8 | 9.8.2.28 |
9.8.2.28 |
| 9.9 | 9.9.2.1 | 9.9.2.1 |
The software is available for download from the Software Center on Cisco.com by navigating to Products > Security > Firewalls > Adaptive Security Appliances (ASA) > ASA 5500-X Series Firewalls, where there is a list of ASA hardware platforms. The majority of these software releases are listed under Interim.
| Cisco FTD Major Release |
First Fixed Release for This Vulnerability |
Recommended Fixed Release for All the Vulnerabilities Described in this Collection of Advisories |
|---|---|---|
| 6.0 |
Not vulnerable1 | Cisco_FTD_SSP_Hotfix_EI-6.1.0.7-2.sh (41xx and 9300 FTD hardware platform) Cisco_FTD_Hotfix_EI-6.1.0.7-2.sh (All FTD hardware platforms except 41xx and 9300) |
| 6.0.1 | Not vulnerable1 | Cisco_FTD_SSP_Hotfix_EI-6.1.0.7-2.sh (41xx and 9300 FTD hardware platform) Cisco_FTD_Hotfix_EI-6.1.0.7-2.sh (All FTD hardware platforms except 41xx and 9300) |
| 6.1.0 | Not vulnerable1 |
Cisco_FTD_SSP_Hotfix_EI-6.1.0.7-2.sh (41xx and 9300 FTD hardware platform) Cisco_FTD_Hotfix_EI-6.1.0.7-2.sh (All FTD hardware platforms except 41xx and 9300) |
| 6.2.0 | Not vulnerable1 |
6.2.0.5 |
| 6.2.1 | Migrate to 6.2.2 Hotfix |
Cisco_FTD_SSP_Hotfix_BD-6.2.2.3-4.sh.REL.tar (41xx and 9300 FTD hardware platforms) Cisco_FTD_SSP_FP2K_Hotfix_BD-6.2.2.3-4.sh.REL.tar (21xx FTD hardware platform) Cisco_FTD_Hotfix_BD-6.2.2.3-4.sh.REL.tar (All other FTD hardware platforms) |
| 6.2.2 | Cisco_FTD_SSP_Hotfix_BD-6.2.2.3-4.sh.REL.tar (41xx and 9300 FTD hardware platforms) Cisco_FTD_SSP_FP2K_Hotfix_BD-6.2.2.3-4.sh.REL.tar (21xx FTD hardware platform) Cisco_FTD_Hotfix_BD-6.2.2.3-4.sh.REL.tar (All other FTD hardware platforms) |
Cisco_FTD_SSP_Hotfix_BD-6.2.2.3-4.sh.REL.tar (41xx and 9300 FTD hardware platforms) Cisco_FTD_SSP_FP2K_Hotfix_BD-6.2.2.3-4.sh.REL.tar (21xx FTD hardware platform) Cisco_FTD_Hotfix_BD-6.2.2.3-4.sh.REL.tar (All other FTD hardware platforms) |
| 6.2.3 | Cisco_FTD_SSP_Hotfix_A-6.2.3.1-10.sh.REL.tar (41xx and 9300 FTD hardware platforms) Cisco_FTD_SSP_FP2K_Hotfix_A-6.2.3.1-10.sh.REL.tar (21xx FTD hardware platform) Cisco_FTD_Hotfix_A-6.2.3.1-10.sh.REL.tar (All other FTD hardware platforms) |
Cisco_FTD_SSP_Hotfix_A-6.2.3.1-10.sh.REL.tar (41xx and 9300 FTD hardware platforms) Cisco_FTD_SSP_FP2K_Hotfix_A-6.2.3.1-10.sh.REL.tar (21xx FTD hardware platform) Cisco_FTD_Hotfix_A-6.2.3.1-10.sh.REL.tar (All other FTD hardware platforms) |
The software is available for download from the Software Center on Cisco.com by navigating to Products > Security > Firewalls> Next-Generation Firewalls (NGFW), where there is a list of possible FTD hardware platforms.
| Cisco AnyConnect Secure Mobility Client Major Release |
First Fixed Release for This Vulnerability |
Recommended Fixed Release for All the Vulnerabilities Described in this Collection of Advisories |
|---|---|---|
| Prior to 4.41 |
Not vulnerable |
Not applicable2 |
| 4.4 | Affected; migrate to 4.6 |
Not applicable2 |
| 4.5 | Affected; migrate to 4.6 |
Not applicable2 |
| 4.6 | Not vulnerable |
Not applicable2 |
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.
This vulnerability was found during the resolution of a Cisco TAC support case.
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.
| Version | Description | Section | Status | Date |
|---|---|---|---|---|
| 1.2 | Updated advisory metadata to reflect affected versions documented in Fixed Software section. | - | Final | 2018-October-05 |
| 1.1 | Added references to ASA and AnyConnect documentation; re-iterated the need to upgrade both ASA/FTD software and the AnyConnect client for a complete fix. | Details, Fixed Releases | Final | 2018-April-19 |
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