Headline
CVE-2022-20928: Cisco Security Advisory: Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software VPN Authorization Bypass Vulnerability
A vulnerability in the authentication and authorization flows for VPN connections in Cisco Adaptive Security Appliance (ASA) Software and Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to establish a connection as a different user. This vulnerability is due to a flaw in the authorization verifications during the VPN authentication flow. An attacker could exploit this vulnerability by sending a crafted packet during a VPN authentication. The attacker must have valid credentials to establish a VPN connection. A successful exploit could allow the attacker to establish a VPN connection with access privileges from a different user.
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.
Cisco ASA, FMC, and FTD Software
To help customers determine their exposure to vulnerabilities in Cisco ASA, FMC, and FTD Software, Cisco provides the Cisco Software Checker. This tool identifies any Cisco security advisories that impact a specific software release and the earliest release that fixes the vulnerabilities that are described in each advisory (“First Fixed”). If applicable, the tool also returns the earliest release that fixes all the vulnerabilities that are described in all the advisories that the Software Checker identifies (“Combined First Fixed”).
To use the tool, go to the Cisco Software Checker page and follow the instructions. Alternatively, use the following form to search for vulnerabilities that affect a specific software release. To use the form, follow these steps:
- Choose which advisories the tool will search-all advisories, only advisories with a Critical or High Security Impact Rating (SIR), or only this advisory.
- Choose the appropriate software.
- Choose the appropriate platform (for Cisco ASA and FTD Software only).
- Enter a release number-for example, 16.2.11 for Cisco ASA Software or 6.6.7 for Cisco FTD Software.
- Click Check.
For instructions on upgrading your FTD device, see Cisco Firepower Management Center Upgrade Guide.