CVE-2019-1693: Cisco Security Advisory: Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software WebVPN Denial of Service 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.

Fixed Releases

Customers are advised to upgrade to an appropriate release as indicated in the applicable table in this section. To ensure a complete upgrade solution, customers should consider that this advisory is part of a collection that includes the following advisories:

• cisco-sa-20190501-asa-csrf: Cisco Adaptive Security Appliance Software Cross-Site Request Forgery Vulnerability
• cisco-sa-20190501-asa-frpwrtd-dos: Cisco Adaptive Security Appliance Software and Cisco Firepower Threat Defense Software TCP Timer Handling Denial of Service Vulnerability
• cisco-sa-20190501-asa-ftd-dos: Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software WebVPN Denial of Service Vulnerability
• cisco-sa-20190501-asa-ftd-entropy: Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software Low-Entropy Keys Vulnerability
• cisco-sa-20190501-asa-ftd-ike-dos: Cisco Adaptive Security Appliance Software and Cisco Firepower Threat Defense Software MOBIKE Denial of Service Vulnerability
• cisco-sa-20190501-asaftd-saml-vpn: Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software VPN SAML Authentication Bypass Vulnerability
• cisco-sa-20190501-asa-ipsec-dos: Cisco Adaptive Security Appliance Software IPsec Denial of Service Vulnerability
• cisco-sa-20190501-firepower-dos: Cisco Firepower Threat Defense Software TCP Ingress Handler Denial of Service Vulnerability
• cisco-sa-20190501-frpwr-dos: Cisco Firepower Threat Defense Software Packet Processing Denial of Service Vulnerability
• cisco-sa-20190501-frpwr-smb-snort: Cisco Firepower Threat Defense Software SMB Protocol Preprocessor Detection Engine Denial of Service Vulnerabilities
• cisco-sa-20190501-sd-cpu-dos: Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software WebVPN Denial of Service Vulnerability

In the following table(s), the left column lists Cisco software releases. The center column indicates whether a release is affected by the vulnerability described in this advisory and the release that includes the fix for this vulnerability. The right column indicates whether a release is affected by all the vulnerabilities described in this collection of advisories and which release includes fixes for those vulnerabilities.

Cisco ASA Software

Cisco ASA Software Release

Recommended Release for This Vulnerability

Recommended Release for All Vulnerabilities Described in the Collection of Advisories

Prior to 9.41

9.4.4.34

9.4.4.34

9.4

9.4.4.34

9.4.4.34

9.51

9.6.4.25

9.6.4.25

9.6

9.6.4.25

9.6.4.25

9.71

9.8.4

9.8.4

9.8

9.8.4

9.8.4

9.9

9.9.2.50

9.9.2.50

9.10

9.10.1.17

9.10.1.17

9.12

Not vulnerable

Not vulnerable

1Cisco ASA Software releases prior to Release 9.4 and Cisco ASA Software Releases 9.5 and 9.7 have reached end of maintenance. Customers should migrate to a supported release that includes the fix for this vulnerability.

Cisco FTD Software

Cisco FTD Software Release

Recommended Release for This Vulnerability

Recommended Release for All Vulnerabilities Described in the Collection of Advisories

6.0

Not vulnerable

6.2.3.12

6.0.1

Not vulnerable

6.2.3.12

6.1.0

Not vulnerable

6.2.3.12

6.2.0

Not vulnerable

6.2.3.12

6.2.1

6.2.3.12

6.2.3.12

6.2.2

6.2.3.12

6.2.3.12

6.2.3

6.2.3.12

6.2.3.12

6.3.0

6.3.0.3

6.3.0.3

6.4.0

Not vulnerable

Not vulnerable

To upgrade to a fixed release of Cisco FTD Software, customers can do one of the following:

• For devices that are managed by using Cisco Firepower Management Center (FMC), use the FMC interface to install the upgrade. After installation is complete, reapply the access control policy.
• For devices that are managed by using Cisco Firepower Device Manager (FDM), use the FDM interface to install the upgrade. After installation is complete, reapply the access control policy.