Cisco has become aware that public exploit code exists for CVE-2020-3580, and this vulnerability is being actively exploited.

Multiple vulnerabilities in the web services interface of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to conduct cross-site scripting (XSS) attacks against a user of the web services interface of an affected device.

The vulnerabilities are due to insufficient validation of user-supplied input by the web services interface of an affected device. An attacker could exploit these vulnerabilities by persuading a user of the interface to click a crafted link. A successful exploit could allow the attacker to execute arbitrary script code in the context of the interface or allow the attacker to access sensitive, browser-based information.

Note: These vulnerabilities affect only specific AnyConnect and WebVPN configurations.

Vulnerable Products

The vulnerabilities affected Cisco products if they were running a vulnerable release of Cisco ASA Software or FTD Software with a vulnerable AnyConnect or WebVPN configuration.

Cisco ASA Software

In the following table, the left column lists the Cisco ASA Software features that were vulnerable at the time of publication. The right column indicates the basic configuration for each feature from the show running-configCLI command. If a device is running a vulnerable release and is configured for one of these features, it is affected by these vulnerabilities.

 

Cisco ASA Software Feature Vulnerable Configuration
AnyConnect Internet Key Exchange Version 2 (IKEv2) Remote Access (with client services)
crypto ikev2 enable <interface_name> client-services port <port #>
AnyConnect SSL VPN
webvpn
 enable <interface_name>
Clientless SSL VPN
webvpn
 enable <interface_name>

Cisco FTD Software

In the following table, the left column lists the Cisco FTD Software features that were vulnerable at the time of publication. The right column indicates the basic configuration for each feature from the show running-configCLI command. If a device is running a vulnerable release and is configured for one of these features, it is affected by these vulnerabilities.

 

Cisco FTD Software Feature Vulnerable Configuration
AnyConnect Internet Key Exchange Version 2 (IKEv2) Remote Access (with client services)1,2
crypto ikev2 enable <interface_name> client-services port <port #>
AnyConnect SSL VPN1,2
webvpn
 enable <interface_name>
1. Remote Access VPN features are first supported in Cisco FTD Software Release 6.2.2.
2. Remote Access VPN features are enabled by using Devices > VPN > Remote Access in Cisco Firepower Management Center (FMC) or by using Device > Remote Access VPN in Cisco Firepower Device Manager (FDM).

Cisco has released software updates that address these vulnerabilities. There are no workarounds that address these vulnerabilities.

Only products listed in the Vulnerable Products section of this advisory are known to be affected by these vulnerabilities.

Cisco has confirmed that these vulnerabilities do not affect Cisco Firepower Management Center (FMC) Software.

Workarounds

  • There are no workarounds that address these vulnerabilities.

Fixed Software

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.

Fixed Releases

Note: It was found that the fix for CVE-2020-3581 was incomplete and is now fixed and tracked by CSCvw53796. The First Fixed Release for These Vulnerabilities column has been updated to account for the complete fix.

Cisco ASA Software

Cisco ASA Software Release First Fixed Release for These Vulnerabilities
Earlier than 9.61 Migrate to a fixed release.
9.61 Migrate to a fixed release.
9.71 Migrate to a fixed release.
9.8 9.8.4.34
9.9 9.9.2.85
9.101 Migrate to a fixed release.
9.12 9.12.4.13
9.13 9.13.1.21
9.14 9.14.2.8
9.15 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 these vulnerabilities.

Cisco FTD Software

Cisco FTD Software Release First Fixed Release for These Vulnerabilities
Earlier than 6.2.21 Migrate to a fixed release.
6.2.2 Migrate to a fixed release.
6.2.3 Migrate to a fixed release.
6.3.0 Migrate to a fixed release.
6.4.0 6.4.0.12 (May 2021)
6.5.0 Migrate to a fixed release.
6.6.0 6.6.42
6.7.0 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 these vulnerabilities.

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.

Source: CISCO