A vulnerability in the cryptographic driver for Cisco Adaptive Security Appliance Software (ASA) and Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the device to reboot unexpectedly. The vulnerability is due to incomplete input validation of a Secure Sockets Layer (SSL) or Transport Layer Security (TLS) ingress packet header. An attacker could exploit this vulnerability by sending a crafted TLS/SSL packet to an interface on the targeted device. An exploit could allow the attacker to cause the device to reload, which will result in a denial of service (DoS) condition. Note: Only traffic directed to the affected system can be used to exploit this vulnerability. This vulnerability affects systems configured in routed and transparent firewall mode and in single or multiple context mode. This vulnerability can be triggered by IPv4 and IPv6 traffic. A valid SSL or TLS session is required to exploit this vulnerability. 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-20190710-asa-ftd-dos
A vulnerability in the cryptographic driver for Cisco Adaptive Security Appliance Software (ASA) and Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the device to reboot unexpectedly.
The vulnerability is due to incomplete input validation of a Secure Sockets Layer (SSL) or Transport Layer Security (TLS) ingress packet header. An attacker could exploit this vulnerability by sending a crafted TLS/SSL packet to an interface on the targeted device. An exploit could allow the attacker to cause the device to reload, which will result in a denial of service (DoS) condition.
Note: Only traffic directed to the affected system can be used to exploit this vulnerability. This vulnerability affects systems configured in routed and transparent firewall mode and in single or multiple context mode. This vulnerability can be triggered by IPv4 and IPv6 traffic. A valid SSL or TLS session is required to exploit this vulnerability.
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-20190710-asa-ftd-dos
This vulnerability affects the following Cisco products if they are running a vulnerable release of Cisco ASA Software or FTD Software:
This vulnerability applies only to the ASA hardware platforms that use a specific cryptographic driver for SSL and TLS packet decryption and encryption. There are multiple features that, when enabled, cause Cisco ASA Software or FTD Software to process SSL/TLS packets. These features include, but are not limited to, the following:
To verify whether a device running Cisco ASA Software or FTD Software could process SSL or TLS packets, use the show asp table socket | include SSL|DTLS command and verify that it returns output. When this command returns any output, the device is vulnerable. When this command returns empty output, the device is not vulnerable. The following example shows the output of the show asp table socket | include SSL|DTLS command from a device that is vulnerable:
BSNS-ASA5505-4# show asp table socket | include SSL|DTLS
SSL 0005aa68 LISTEN x.x.x.x:443 0.0.0.0:*
SSL 002d9e38 LISTEN x.x.x.x:8443 0.0.0.0:*
DTLS 0018f7a8 LISTEN 10.0.0.250:443 0.0.0.0:*
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:
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 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.
Customers are advised to upgrade to an appropriate release as indicated in the applicable table in this section. In the following table(s), the left column lists Cisco software releases and the right column indicates whether a release is affected by the vulnerability described in this advisory and the release that includes the fix for this vulnerability
Cisco ASA Software
Cisco ASA Software Release | First Fixed Release for This Vulnerability |
---|---|
Prior to 9.41 |
9.4.4.36 |
9.4 | 9.4.4.36 |
9.51 | 9.6.4.29 |
9.6 | 9.6.4.29 |
9.71 | 9.8.4.3 |
9.8 | 9.8.4.3 |
9.9 | 9.9.2.52 |
9.10 | 9.10.1.22 |
9.12 | 9.12.2 |
Cisco FTD Software
Cisco FTD Software Release | First Fixed Release for This Vulnerability |
---|---|
6.01 |
6.2.3.13 |
6.0.11 | 6.2.3.13 |
6.1.0 | 6.2.3.13 |
6.2.0 | 6.2.3.13 |
6.2.1 | 6.2.3.13 |
6.2.2 | 6.2.3.13 |
6.2.3 | 6.2.3.13 |
6.3.0 | Cisco_FTD_Hotfix_AA-6.3.0.4-2 or 6.3.0.4 (August 2019) |
6.4.0 | 6.4.0.2 |
To upgrade to a fixed release of Cisco FTD Software, customers can do one of the following:
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 |
---|---|---|---|---|
1.1 | Added the hotfix information for the FTD 6.3.0 release. | Fixed Software | Final | 2019-July-11 |
1.0 | Initial public release. | - | Final | 2019-July-10 |
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