Summary

• Multiple vulnerabilities in the Server Message Block (SMB) Protocol preprocessor detection engine for Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, adjacent or remote attacker to cause 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-20190501-frpwr-smb-snort

Affected Products

• Vulnerable Products

  These vulnerabilities affect the following Cisco products that are running a vulnerable release of Cisco FTD Software:

  • 3000 Series Industrial Security Appliances (ISAs)
  • Adaptive Security Appliance (ASA) 5500-X Series Firewalls
  • ASA 5500-X Series with FirePOWER Services
  • Advanced Malware Protection (AMP) for Networks for FirePOWER 7000 Series Appliances
  • AMP for Networks for FirePOWER 8000 Series Appliances
  • Firepower 2100 Series
  • Firepower 4100 Series
  • FirePOWER 7000 Series Appliances
  • FirePOWER 8000 Series Appliances
  • Firepower 9300 Security Appliances
  • Firepower Threat Defense for Integrated Services Routers (ISRs)
  • FTD Virtual (FTDv)
  • Next-Generation Intrusion Prevention System (NGIPS)

  For information about which Cisco FTD Software releases are vulnerable, see the Fixed Software section of this advisory.

  These vulnerabilities may also affect the open-source Snort project. For more information, see the Snort website.

  Determining the Cisco FTD Software Release

  To determine which Cisco FTD Software release is running on a device, administrators can log in to the device, use the show version command in the CLI, and refer to the output of the command. The following example shows the output of the command for a device that is running Cisco FTD Software Release 6.2.0:

  > show version
  
  ---------------------[ ftd ]---------------------
  Model : Cisco ASA5525-X Threat Defense (75) Version 6.2.0 (Build 362)
  UUID : 2849ba3c-ecb8-11e6-98ca-b9fc2975893c
  Rules update version : 2017-03-15-001-vrt
  VDB version : 279
  ----------------------------------------------------

  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:

  • Adaptive Security Appliance (ASA) Software
  • Firepower Management Center
  • Meraki MX Security Appliances

Details

• Two vulnerabilities in the SMB Protocol preprocessor detection engine for Cisco FTD Software could allow an adjacent or remote attacker to cause a DoS condition.

  The vulnerabilities are not dependent on one another; exploitation of one of the vulnerabilities is not required to exploit the other vulnerability.

  Details about the vulnerabilities are as follows.

  Cisco Firepower Threat Defense Software SMB Protocol Preprocessor Detection Engine Low System Memory Denial of Service Vulnerability

  A vulnerability in the SMB Protocol preprocessor detection engine for Cisco FTD Software could allow an unauthenticated, adjacent attacker to cause the device to run low on system memory, which may cause the device to stop forwarding traffic. A manual reload of the device may be required to clear the condition.

  The vulnerability is due to incorrect SMB ingress packet processing for specific SMB packet types. An attacker could exploit this vulnerability by sending a steady stream of crafted SMB packets to the targeted device from the local subnet. A successful exploit could allow the attacker to cause the device to run low on system memory, which could prevent the Snort process from forwarding traffic. This vulnerability can be exploited using IPv4 or IPv6 with either SMB Version 2 (SMBv2) or SMB Version 3 (SMBv3) network traffic.

  The Common Vulnerabilities and Exposures (CVE) ID for this vulnerability is: CVE-2019-1696

  The Security Impact Rating (SIR) for this vulnerability is: High

  Cisco Firepower Threat Defense Software SMB Protocol Preprocessor Detection Engine Denial of Service Vulnerability

  A vulnerability in the SMB Protocol preprocessor detection engine for Cisco FTD Software could allow an unauthenticated, remote attacker to cause the Snort process to unexpectedly restart, resulting in a denial of service (DoS) condition.

  The vulnerability is due to incorrect SMB ingress packet processing for specific SMB packet types. An attacker could exploit this vulnerability by sending a crafted SMB connection to the targeted device. A successful exploit could allow the attacker to cause the Snort process to crash. This vulnerability can be exploited using IPv4 or IPv6 with either SMBv2 or SMBv3 network traffic.

  The CVE ID for this vulnerability is: CVE-2019-1704

  The SIR for this vulnerability is: High

Indicators of Compromise

• The Cisco Firepower Threat Defense Software SMB Protocol Preprocessor Detection Engine Low System Memory Denial of Service Vulnerability could cause the device to run low on system memory, which could cause the Snort process to restart unexpectedly. If the following error log is observed, customers are advised to contact the Cisco Technical Assistance Center (TAC) to determine whether the vulnerability has been exploited on the device.

  Firepower-module1 kernel: [1111040.969265] snort invoked oom-killer: gfp_mask=0xd0, order=0, oom_score_adj=0

Workarounds

• There are no workarounds that address these vulnerabilities.

Fixed Software

• Cisco has released free software updates that address the vulnerabilities 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 vulnerabilities described in this advisory and the release that includes the fix for these vulnerabilities. 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 FTD Software

  Cisco FTD Software Release	Recommended Release for These Vulnerabilities	Recommended Release for All Vulnerabilities Described in the Collection of Advisories
  6.0	6.2.3.12	6.2.3.12
  6.0.1	6.2.3.12	6.2.3.12
  6.1.0	6.2.3.12	6.2.3.12
  6.2.0	6.2.3.12	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	Not vulnerable	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.

  The Snort version that is installed depends on the FMC 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

• These vulnerabilities were found during the resolution of a Cisco TAC support case.

URL

• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190501-frpwr-smb-snort

Revision History

• Version	Description	Section	Status	Date
  1.1	Updated the FTD fixed releases table to indicate that FTD Software Release 6.3.0.3 is available.	Fixed Software	Final	2019-May-02
  1.0	Initial public release.	—	Final	2019-May-01

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