Headline
CVE-2021-1445: Cisco Security Advisory: Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software Web Services VPN Denial of Service Vulnerabilities
Multiple vulnerabilities in Cisco Adaptive Security Appliance (ASA) Software and Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. These vulnerabilities are due to lack of proper input validation of the HTTPS request. An attacker could exploit these vulnerabilities by sending a crafted HTTPS request to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition. Note: This vulnerability affects only specific AnyConnect and WebVPN configurations. For more information, see the Vulnerable Products section.
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.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 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
In the following table(s), the left column lists Cisco software releases. The second and third columns indicate whether a release is affected by the vulnerabilities described in this advisory and the first release that includes the fix for each vulnerability. The right column indicates whether a release is affected by any of the vulnerabilities described in the collection of advisories and which release includes fixes for those vulnerabilities.
Cisco ASA Software
Cisco ASA Software Release
CVE-2021-1445 (CSCvv56644)
CVE-2021-1504 (CSCvv65184)
Fixed Release for all Vulnerabilities Described in the Bundle of Advisories
Earlier than 9.71
Not vulnerable
Not vulnerable
Migrate to a fixed release.
9.71
Migrate to a fixed release.
Migrate to a fixed release.
Migrate to a fixed release.
9.8
9.8.4.34
9.8.4.35
9.8.4.35
9.9
9.9.2.85
9.9.2.85
9.9.2.85
9.10
Migrate to a fixed release.
Migrate to a fixed release.
Migrate to a fixed release.
9.12
9.12.4.13
9.12.4.10
9.12.4.18
9.13
9.13.1.21
9.13.1.21
9.13.1.21
9.14
9.14.2.8
9.14.2.4
9.14.2.13
9.15
9.15.1.7
9.15.1.7
9.15.1.15
1. Cisco ASA Software releases 9.7 and earlier, as well as Release 9.10, have reached end of software maintenance. Customers are advised to migrate to a supported release that includes the fix for this vulnerability.
Cisco FTD Software
Cisco FTD Software Release
CVE-2021-1445 (CSCvv56644)
CVE-2021-1504 (CSCvv65184)
Recommended Release for All the Vulnerabilities Described in the Bundle of Advisories
Earlier than 6.2.21
Migrate to a fixed release.
Migrate to a fixed release.
Migrate to a fixed release.
6.2.2
Migrate to a fixed release.
Migrate to a fixed release.
Migrate to a fixed release.
6.2.3
Migrate to a fixed release.
Migrate to a fixed release.
Migrate to a fixed release.
6.3.0
Migrate to a fixed release.
Migrate to a fixed release.
Migrate to a fixed release.
6.4.0
6.4.0.12 (May 2021)
6.4.0.12 (May 2021)
6.4.0.12 (May 2021)
6.5.0
Migrate to a fixed release.
Migrate to a fixed release.
Migrate to a fixed release
6.6.0
6.6.4
6.6.4
6.6.42
6.7.0
6.7.0.1
6.7.0.1
6.7.0.2
1. Cisco FMC and FTD Software releases 6.0.1 and earlier, as well as releases 6.2.0 and 6.2.1, have reached end of software maintenance. Customers are advised to migrate to a supported release that includes the fix for this vulnerability.
2. The First Fixed Release for the 6.6.0 code train was 6.6.3; however, due to upgrade issues associated with CSCvx86231 the recommended release is 6.6.4.
To upgrade to a fixed release of Cisco FTD Software, 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.