Cisco Security Advisory
Click Icon to Copy Verbose Score
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H/E:X/RL:X/RC:X
-
A vulnerability in the cryptographic hardware accelerator driver of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a temporary denial of service (DoS) condition.
The vulnerability exists because the affected devices have a limited amount of Direct Memory Access (DMA) memory and the affected software improperly handles resources in low-memory conditions. An attacker could exploit this vulnerability by sending a sustained, high rate of malicious traffic to an affected device to exhaust memory on the device. A successful exploit could allow the attacker to exhaust DMA memory on the affected device, which could cause the device to reload and result in a temporary DoS condition.
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://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20181003-asa-dma-dos
-
Vulnerable Products
This vulnerability affects the following Cisco products if they are running a vulnerable release of Cisco Adaptive Security Appliance (ASA) Software or Cisco Firepower Threat Defense (FTD) Software:
- ASA 5506-X with FirePOWER Services
- ASA 5506H-X with FirePOWER Services
- ASA 5506W-X with FirePOWER Services
- ASA 5508-X with FirePOWER Services
- ASA 5516-X with FirePOWER Services
This vulnerability also affects the preceding products if FirePOWER Services are not installed or enabled.
For information about which Cisco ASA Software and Cisco FTD Software releases are vulnerable, see the Fixed Software section of this advisory.
Determine the Cisco ASA Software Release
To determine which Cisco ASA 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 ASA Software Release 9.4(4):
ciscoasa# show version | include Version Cisco Adaptive Security Appliance Software Version 9.4(4) Device Manager Version 7.4(1) . . .
If a device is managed by using Cisco Adaptive Security Device Manager (ASDM), administrators can also determine which release is running on a device by referring to the release information in the table that appears in the Cisco ASDM log in window or the Device Dashboard tab of the Cisco ASDM Home pane.
Determine 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 this vulnerability.
Cisco has confirmed that this vulnerability does not affect the following Cisco products:
- 3000 Series Industrial Security Appliances (ISAs)
- 7600 Series ASA Services Module
- Adaptive Security Virtual Appliance (ASAv)
- ASA 1000V Cloud Firewall
- ASA 5512-X with FirePOWER Services
- ASA 5515-X with FirePOWER Services
- ASA 5525-X with FirePOWER Services
- ASA 5545-X with FirePOWER Services
- ASA 5555-X with FirePOWER Services
- ASA 5585-X with FirePOWER SSP-10, SSP-20, SSP-40, or SSP-60
- ASA 5505 Adaptive Security Appliance
- ASA 5510 Adaptive Security Appliance
- ASA 5512-X Adaptive Security Appliance
- ASA 5515-X Adaptive Security Appliance
- ASA 5520 Adaptive Security Appliance
- ASA 5525-X Adaptive Security Appliance
- ASA 5540 Adaptive Security Appliance
- ASA 5545-X Adaptive Security Appliance
- ASA 5550 Adaptive Security Appliance
- ASA 5555-X Adaptive Security Appliance
- ASA 5580 Adaptive Security Appliance
- ASA 5585-X Adaptive Security Appliance
- Catalyst 6500 Series ASA Services Module
- Firepower 2100 Series Security Appliances
- Firepower 4100 Series Security Appliances
- FirePOWER 7000 Series Appliances
- FirePOWER 8000 Series Appliances
- Firepower 9300 ASA Security Module
- Firepower Threat Defense Virtual (FTDv)
-
The vulnerability described in this advisory exists because the affected devices have a limited amount of DMA memory and the affected software improperly handles resources in low-memory conditions. When the affected software cannot allocate DMA memory, the software may cause a device to crash and reload, resulting in a temporary DoS condition.
To address this vulnerability, Cisco corrected how the software handles resources in low-memory conditions. Cisco also implemented a DMA_MEM_ALLOC_FAILED protocol stack counter that administrators can use to determine whether and how many DMA memory allocation failures have occurred on a device. Sustained periods of DMA memory allocation failures could adversely impact traffic that is sent through a device.
To check the value of the DMA_MEM_ALLOC_FAILED counter, administrators can use the show counters privileged EXEC command in the device CLI, as shown in the following example:
ciscoasa# show counters Protocol Counter Value Context
.
.
.
CRYPTO DMA_MEM_ALLOC_FAILED 1 SummaryIf the value of the DMA_MEM_ALLOC_FAILED counter increases quickly for a sustained period of time, administrators should contact the Cisco Technical Assistance Center (TAC) for further investigation.
-
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.htmlAdditionally, 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.htmlCustomers 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 help ensure a complete upgrade solution, consider that this advisory is part of a collection that includes the following advisories:
- cisco-sa-20181003-asa-dma-dos: Cisco Adaptive Security Appliance Direct Memory Access Denial of Service Vulnerability
- cisco-sa-20181003-ftd-inspect-dos: Cisco Firepower Threat Defense Software FTP Inspection Denial of Service Vulnerability
In the following table(s), the left column lists releases of Cisco software. The center column indicates whether a release is affected by the vulnerability described in this advisory and the first 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 First Fixed Release for This Vulnerability First Fixed Release for All Vulnerabilities Described in the Collection of Advisories Prior to 9.11 Not vulnerable2 Not vulnerable2 9.1 Not vulnerable2 Not vulnerable2 9.21 Not vulnerable2 Not vulnerable2 9.31 Migrate to 9.4.4.22 Migrate to 9.4.4.22 9.4 9.4.4.22 9.4.4.22 9.51 Migrate to 9.6.4.14 Migrate to 9.6.4.14 9.6 9.6.4.14 9.6.4.14 9.71 Migrate to 9.8.3.8 Migrate to 9.8.3.8 9.8 9.8.3.8 9.8.3.8 9.9 9.9.2.18 9.9.2.18 1 Cisco ASA Software releases prior to Release 9.1 and Cisco ASA Software Releases 9.2, 9.3, 9.5, and 9.7 have reached the end-of-software-maintenance milestone. Customers are advised to migrate to a supported release that includes the fix for this vulnerability.
2 Cisco ASA Software releases prior to Release 9.3 are not supported on Cisco ASA 5506-X, 5506H-X, 5506W-X, 5508-X, and 5516-X Appliances.
Cisco FTD Software
Cisco FTD Software Release First Fixed Release for This Vulnerability First Fixed Release for All Vulnerabilities Described in the Collection of Advisories 6.0 Migrate to 6.1.0.7 Migrate to 6.1.0.7 6.0.1 Migrate to 6.1.0.7 Migrate to 6.1.0.7 6.1.0 6.1.0.7 6.1.0.7 6.2.0 6.2.0.7 (future release) 6.2.0.7 (future release) 6.2.1 Not vulnerable Migrate to 6.2.2.5 (future release) 6.2.2 6.2.2.5 (future release) 6.2.2.5 (future release) 6.2.3 6.2.3.4 6.2.3.4 To upgrade to a fixed release of Cisco Firepower System 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 and, after installation is complete, reapply the access control policy. The Snort version that is installed depends on the FMC release.
- For devices that are managed by using Cisco Adaptive Security Device Manager (ASDM) or Cisco Firepower Device Manager (FDM), use the ASDM or FDM interface to install the upgrade and, after installation is complete, reapply the access control policy.
-
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 internal security testing.
-
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.
-
Show LessVersion Description Section Status Date 1.1 Updated advisory metadata to match advisory text. — Final 2018-October-29 1.0 Initial public release. — Final 2018-October-03
-
THIS DOCUMENT IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. YOUR USE OF THE INFORMATION ON THE DOCUMENT OR MATERIALS LINKED FROM THE DOCUMENT IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS DOCUMENT AT ANY TIME.
A standalone copy or paraphrase of the text of this document that omits the distribution URL is an uncontrolled copy and may lack important information or contain factual errors. The information in this document is intended for end users of Cisco products.