Cisco AnyConnect Secure Mobility Client for Windows DLL Hijacking Vulnerability
Cisco Security Advisory
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More information can be found in Cisco Security Vulnerability Policy available at https://sec.cloudapps.cisco.com/security/center/resources/security_vulnerability_policy.html
cisco-sa-anyconnect-dll-F26WwJW
Final
1.2
1.0
2020-07-31T18:10:27
Initial public release.
1.1
2020-08-13T17:32:33
Proof-of-concept exploit code is available
1.2
2022-10-25T13:15:17
Updated Exploitation and Public Announcements section because Cisco became aware of active exploitation attempts.
2020-08-05T16:00:00
2022-10-25T13:15:17
TVCE
A vulnerability in the interprocess communication (IPC) channel of Cisco AnyConnect Secure Mobility Client for Windows could allow an authenticated, local attacker to perform a DLL hijacking attack. To exploit this vulnerability, the attacker would need to have valid credentials on the Windows system.
The vulnerability is due to insufficient validation of resources that are loaded by the application at run time. An attacker could exploit this vulnerability by sending a crafted IPC message to the AnyConnect process. A successful exploit could allow the attacker to execute arbitrary code on the affected machine with SYSTEM privileges. To exploit this vulnerability, the attacker would need to have valid credentials on the Windows system.
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-anyconnect-dll-F26WwJW ["https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-anyconnect-dll-F26WwJW"]
This vulnerability affects Cisco AnyConnect Secure Mobility Client for Windows releases earlier than Release 4.9.00086.
Only products listed in the Vulnerable Products ["#vp"] section of this advisory are known to be affected by this vulnerability.
Cisco has confirmed that this vulnerability does not affect the following Cisco products:
AnyConnect Secure Mobility Client for MacOS
AnyConnect Secure Mobility Client for Linux
AnyConnect Secure Mobility Client for mobile device operating systems such as iOS, Android, and Universal Windows Platform
There are no workarounds that address this vulnerability.
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 ["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 ["https://sec.cloudapps.cisco.com/security/center/resources/security_vulnerability_policy.html#fixes"], customers are advised to regularly consult the advisories for Cisco products, which are available from the Cisco Security Advisories page ["https://www.cisco.com/go/psirt"], 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 ["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
Cisco fixed this vulnerability in Cisco AnyConnect Secure Mobility Client for Windows releases 4.9.00086 and later.
To download the software from the Software Center ["https://software.cisco.com/download/"] on Cisco.com, do the following:
Click Browse all.
Choose Security > VPN and Endpoint Security Clients > Cisco VPN Clients > AnyConnect Secure Mobility Client > AnyConnect Secure Mobility Client v4.x.
Choose the release from the left pane of the AnyConnect Secure Mobility Client v4.x page.
To learn about Cisco security vulnerability disclosure policies and publications, see the Security Vulnerability Policy ["https://sec.cloudapps.cisco.com/security/center/resources/security_vulnerability_policy.html"]. This document also contains instructions for obtaining fixed software and receiving security vulnerability information from Cisco.
The Cisco Product Security Incident Response Team (PSIRT) is aware that proof-of-concept exploit code is available for the vulnerability that is described in this advisory.
In October 2022, the Cisco 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.
Cisco would like to thank Antoine Goichot of PwC Luxembourg's Cybersecurity team for reporting this vulnerability.
THIS DOCUMENT IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. YOUR USE OF THE INFORMATION ON THE DOCUMENT OR MATERIALS LINKED FROM THE DOCUMENT IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS DOCUMENT AT ANY TIME.
A standalone copy or paraphrase of the text of this document that omits the distribution URL is an uncontrolled copy and may lack important information or contain factual errors. The information in this document is intended for end users of Cisco products.
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-anyconnect-dll-F26WwJW
Cisco AnyConnect Secure Mobility Client for Windows DLL Hijacking Vulnerability
Cisco AnyConnect Secure Mobility Client
vuln-CVE-2020-3433
CSCvu14943
CSCvu14943
Complete.
CVE-2020-3433
CVRFPID-109810
7.8
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
There are no workarounds that address this vulnerability.
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-anyconnect-dll-F26WwJW
Cisco AnyConnect Secure Mobility Client for Windows DLL Hijacking Vulnerability