Summary

• A vulnerability 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 retrieve memory contents on an affected device, which could lead to the disclosure of confidential information.

  The vulnerability is due to a buffer tracking issue when the software parses invalid URLs that are requested from the web services interface. An attacker could exploit this vulnerability by sending a crafted GET request to the web services interface. A successful exploit could allow the attacker to retrieve memory contents, which could lead to the disclosure of confidential information.

  Note: This vulnerability affects only specific AnyConnect and WebVPN configurations. For more information, see the Vulnerable Products section.

  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://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-info-disclose-9eJtycMB

  This advisory is part of the May 2020 Cisco ASA, FMC, and FTD Software Security Advisory Bundled Publication, which includes 12 Cisco Security Advisories that describe 12 vulnerabilities. For a complete list of the advisories and links to them, see Cisco Event Response: May 2020 Cisco ASA, FMC, and FTD Software Security Advisory Bundled Publication.

Affected Products

• Vulnerable Products

  This vulnerability affects Cisco products if they are 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 are vulnerable. The right column indicates the basic configuration for the feature from the show running-config CLI command. If the device is running a vulnerable release and is configured for one of these features, it is vulnerable.

  Cisco ASA Software Feature	Vulnerable Configuration
  AnyConnect 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 are vulnerable. The right column indicates the basic configuration for the feature from the show running-config CLI command. If the device is running a vulnerable release and is configured for one of these features, it is vulnerable.

  Cisco FTD Software Feature	Vulnerable Configuration
  AnyConnect 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 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).
  2. Remote Access VPN features are first supported in Cisco FTD Software Release 6.2.2.

  Products Confirmed Not Vulnerable

  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.

Details

• The confidential information that could be disclosed is memory on the system heap. The contents of this memory can be different on each system and at different times but can include web cookies for the AnyConnect and WebVPN features, usernames, email addresses, certificates, and actual heap addresses.

Workarounds

• There are no workarounds that address this vulnerability.

Fixed Software

• 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 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 center column indicates whether a release is affected by the vulnerability described in this advisory and the first release that includes the fix for this vulnerability. The right column indicates whether a release is affected by any of the vulnerabilities described in this bundle and which release includes fixes for those vulnerabilities.

  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 9.51	Migrate to a fixed release.	Migrate to a fixed release.
  9.51	Migrate to a fixed release.	Migrate to a fixed release.
  9.6	9.6.4.41	Migrate to a fixed release.
  9.71	Migrate to a fixed release.	Migrate to a fixed release.
  9.8	9.8.4.20	9.8.4.20
  9.9	9.9.2.67	9.9.2.67
  9.10	9.10.1.40	9.10.1.40
  9.12	9.12.3.9	9.12.3.9
  9.13	9.13.1.10	9.13.1.10
  9.14	Not vulnerable.	Not vulnerable.

  1. Cisco ASA Software releases 9.5 and earlier, as well as Release 9.7, 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	First Fixed Release for This Vulnerability	First Fixed Release for All Vulnerabilities Described in the Bundle of Advisories
  Earlier than 6.2.31	Migrate to a fixed release.	Migrate to a fixed release.
  6.2.3	6.2.3.16 (June 2020) Cisco_FTD_Hotfix_DT-6.2.3.16-3.sh.REL.tar Cisco_FTD_SSP_FP2K_Hotfix_DT-6.2.3.16-3.sh.REL.tar Cisco_FTD_SSP_Hotfix_DT-6.2.3.16-3.sh.REL.tar	6.2.3.16 (June 2020) Cisco_FTD_Hotfix_DT-6.2.3.16-3.sh.REL.tar Cisco_FTD_SSP_FP2K_Hotfix_DT-6.2.3.16-3.sh.REL.tar Cisco_FTD_SSP_Hotfix_DT-6.2.3.16-3.sh.REL.tar
  6.3.0	6.3.0.6 (future release) Cisco_FTD_Hotfix_AO-6.3.0.6-2.sh.REL.tar Cisco_FTD_SSP_FP2K_Hotfix_ AO-6.3.0.6-2.sh.REL.tar Cisco_FTD_SSP_Hotfix_ AO-6.3.0.6-2.sh.REL.tar	6.3.0.6 (future release) Cisco_FTD_Hotfix_AO-6.3.0.6-2.sh.REL.tar Cisco_FTD_SSP_FP2K_Hotfix_ AO-6.3.0.6-2.sh.REL.tar Cisco_FTD_SSP_Hotfix_ AO-6.3.0.6-2.sh.REL.tar
  6.4.0	6.4.0.9	6.4.0.9
  6.5.0	6.5.0.5 (future release) Cisco_FTD_Hotfix_H-6.5.0.5-2.sh.REL.tar and later Cisco_FTD_SSP_FP1K_Hotfix_H-6.5.0.5-2.sh.REL.tar and later Cisco_FTD_SSP_FP2K_Hotfix_H-6.5.0.5-2.sh.REL.tar and later Cisco_FTD_SSP_Hotfix_H-6.5.0.5-2.sh.REL.tar and later	6.5.0.5 (future release) Cisco_FTD_Hotfix_H-6.5.0.5-2.sh.REL.tar and later Cisco_FTD_SSP_FP1K_Hotfix_H-6.5.0.5-2.sh.REL.tar and later Cisco_FTD_SSP_FP2K_Hotfix_H-6.5.0.5-2.sh.REL.tar and later Cisco_FTD_SSP_Hotfix_H-6.5.0.5-2.sh.REL.tar and later
  6.6.0	Not vulnerable.	6.6.0

  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:

  • 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

• In February 2024, the Cisco Product Security Incident Response Team (PSIRT) became aware of additional attempted exploitation of this vulnerability in the wild. Cisco continues to strongly recommend that customers upgrade to a fixed software release to remediate this vulnerability.

Source

• Cisco would like to thank Mikhail Klyuchnikov and Nikita Abramov of Positive Technologies for reporting this vulnerability.

URL

• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-info-disclose-9eJtycMB

Revision History

• Version	Description	Section	Status	Date
  1.5	Updated Exploitation and Public Announcements	Exploitation and Public Announcements	Final	2024-FEB-21
  1.4	Updated fixed release information for FTD Release 6.4.0.	Fixed Releases	Final	2020-JUN-02
  1.3	Updated Hot Fixes for FTD releases 6.4.0 and 6.5.0.	Fixed Releases	Final	2020-MAY-15
  1.2	Updated ASA Fixed Releases table with 9.6 release.	Fixed Software	Final	2020-MAY-11
  1.1	Updated ASA Fixed Releases table to indicate 9.10.1.40 as the correct fixed release instead of 9.10.1.39.	Fixed Software	Final	2020-MAY-06
  1.0	Initial public release.	—	Final	2020-MAY-06

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