Summary

• Update June 28, 2021: Cisco has become aware that public exploit code exists for CVE-2020-3580, and this vulnerability is being actively exploited.

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  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. For more information, see the Vulnerable Products section.

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

  This advisory is available at the following link:
  https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-xss-multiple-FCB3vPZe

Affected Products

• Vulnerable Products

  At the time of publication, these 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.

  For information about which Cisco software releases were vulnerable at the time of publication, see the Fixed Software section of this advisory. See the Details section in the bug ID(s) at the top of this advisory for the most complete and current information.

  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-config CLI 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 client-services port
  AnyConnect SSL VPN	webvpn enable
  Clientless SSL VPN	webvpn enable

  
  

  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-config CLI 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 client-services port
  AnyConnect SSL VPN1,2	webvpn enable

  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).

  
  

  Products Confirmed Not Vulnerable

  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

  At the time of publication, the release information in the following table(s) was accurate. See the Details section in the bug ID(s) at the top of this advisory for the most complete and current information.

  The left column lists Cisco software releases, and the right column indicates whether a release was affected by the vulnerabilities described in this advisory and which release included the fix for these vulnerabilities.

  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.

Exploitation and Public Announcements

• The Cisco Product Security Incident Response Team (PSIRT) is aware that public exploit code exists for CVE-2020-3580, and this vulnerability is being actively exploited.

Source

• Cisco would like to thank the following security researchers:

  • Abdulrahman Nour and Ahmed Aboul-Ela of RedForce, Mikhail Klyuchnikov and Nikita Abramov of Positive Technologies, and Phil Purviance for independently reporting CVE-2020-3580
  • Maxim Suslov and Phil Purviance for independently reporting CVE-2020-3581
  • Phil Purviance for reporting CVE-2020-3582
  • Maxim Suslov and Phil Purviance for independently reporting CVE-2020-3583

URL

• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-xss-multiple-FCB3vPZe

Revision History

• Version	Description	Section	Status	Date
  3.1	Indicated that public exploit code is available and active exploitation is occurring.	Summary, Exploitation and Public Announcements	Final	2021-JUN-28
  3.0	Updated the fixed release information for CVE-2020-3581, which is tracked by Cisco Bug ID CSCvw53796. These CVEs have previously been disclosed.	Summary, Fixed Software, Exploitation and Public Announcements	Final	2021-APR-28
  2.0	Updated the Summary section to provide information on a new vulnerability affecting fixed release recommendations for code trains 9.13 and 9.14.	Summary	Final	2020-OCT-22
  1.1	Added a security researcher for CVE-2020-3580.	Source	Final	2020-OCT-22
  1.0	Initial public release.	-	Final	2020-OCT-21

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