A vulnerability in the Session Initiation Protocol (SIP) inspection module of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to improper parsing of SIP messages. An attacker could exploit this vulnerability by sending a malicious SIP packet through an affected device. A successful exploit could allow the attacker to trigger an integer underflow, causing the software to try to read unmapped memory and resulting in a crash. 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-20191002-asa-ftd-sip-dos This advisory is part of the October 2019 Cisco ASA, FMC, and FTD Software Security Advisory Bundled Publication, which includes 10 Cisco Security Advisories that describe 18 vulnerabilities. For a complete list of the advisories and links to them, see Cisco Event Response: October 2019 Cisco ASA, FMC, and FTD Software Security Advisory Bundled Publication.
A vulnerability in the Session Initiation Protocol (SIP) inspection module of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device.
The vulnerability is due to improper parsing of SIP messages. An attacker could exploit this vulnerability by sending a malicious SIP packet through an affected device. A successful exploit could allow the attacker to trigger an integer underflow, causing the software to try to read unmapped memory and resulting in a crash.
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-20191002-asa-ftd-sip-dos
This vulnerability affects Cisco products that are running a vulnerable release of Cisco ASA Software or Cisco FTD Software and that have the SIP inspection feature enabled. SIP inspection is enabled by default in Cisco ASA Software and FTD Software. For detailed information about the default settings for application inspection policies, refer to the Cisco ASA Series Firewall CLI Configuration Guide.
For information about which Cisco ASA Software and FTD Software releases are vulnerable, see the Fixed Software section of this advisory.
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 Cisco Firepower Management Center (FMC) Software.
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.
Cisco ASA Software
| Cisco ASA Software Release | First Fixed Release for This Vulnerability | First Fixed Release for All Vulnerabilities Described in the Bundle of Advisories |
|---|---|---|
| Earlier than 9.41 |
Migrate to a fixed release. |
Migrate to a fixed release. |
| 9.41 | 9.4.4.37 | Migrate to a fixed release. |
| 9.51 | Migrate to a fixed release. | Migrate to a fixed release. |
| 9.6 | 9.6.4.34 | 9.6.4.34 |
| 9.71 | Migrate to a fixed release. | Migrate to a fixed release. |
| 9.8 | 9.8.4.7 | 9.8.4.10 |
| 9.9 | 9.9.2.56 | Migrate to a fixed release. |
| 9.10 | 9.10.1.27 | 9.10.1.30 |
| 9.12 | 9.12.2.1 | 9.12.2.5 |
| 9.13 | Not vulnerable. |
Not vulnerable. |
Cisco FTD Software
| Cisco FTD Software Release | First Fixed Release for This Vulnerability | First Fixed Release for All Vulnerabilities Described in the Bundle of Advisories |
|---|---|---|
| Earlier than 6.1.01 | Migrate to a fixed release. | Migrate to a fixed release. |
| 6.1.0 | Migrate to a fixed release. | Migrate to a fixed release. |
| 6.2.0 | Migrate to a fixed release. | Migrate to a fixed release. |
| 6.2.1 | Migrate to a fixed release. | Migrate to a fixed release. |
| 6.2.2 | Migrate to a fixed release. | Migrate to a fixed release. |
| 6.2.3 | 6.2.3.15 | Migrate to a fixed release. |
| 6.3.0 | 6.3.0.4 | 6.4.0.4 |
| 6.4.0 | 6.4.0.4 |
6.4.0.4 |
| 6.5.0 | Not vulnerable. | Not vulnerable. |
1. Cisco FMC and FTD Software releases 6.0.1 and earlier have reached end of software maintenance. Customers are advised to migrate to a supported release that includes the fix for this vulnerability.
To upgrade to a fixed release of Cisco FTD Software, customers can do one of the following:
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.
| Version | Description | Section | Status | Date |
|---|---|---|---|---|
| 1.0 | Initial public release. | - | Final | 2019-October-02 |
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.
Vulmon