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AUSCERT External Security Bulletin Redistribution
ESB-2020.2680.2
Cisco AnyConnect Secure Mobility Client for Windows
14 August 2020
===========================================================================
AusCERT Security Bulletin Summary
---------------------------------
Product: Cisco AnyConnect Secure Mobility Client for Windows
Publisher: Cisco Systems
Operating System: Windows
Impact/Access: Increased Privileges -- Existing Account
Denial of Service -- Existing Account
Resolution: Patch/Upgrade
CVE Names: CVE-2020-3435 CVE-2020-3434 CVE-2020-3433
Original Bulletin:
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-anyconnect-dll-F26WwJW
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-anyconnect-dos-feXq4tAV
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-anyconnect-profile-7u3PERKF
Comment: This bulletin contains three (3) Cisco Systems security advisories.
Revision History: August 14 2020: Cisco advises that proof-of-concept
exploit code is now available for
CVE-2020-3433.
- --------------------------BEGIN INCLUDED TEXT--------------------
Cisco AnyConnect Secure Mobility Client for Windows DLL Hijacking Vulnerability
Priority: High
Advisory ID: cisco-sa-anyconnect-dll-F26WwJW
First Published: 2020 August 5 16:00 GMT
Last Updated: 2020 August 13 17:32 GMT
Version 1.1: Final
Workarounds: No workarounds available
Cisco Bug IDs: CSCvu14943
CVE-2020-3433
CWE-427
Summary
o 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://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/
cisco-sa-anyconnect-dll-F26WwJW
Affected Products
o Vulnerable Products
This vulnerability affects Cisco AnyConnect Secure Mobility Client for
Windows releases earlier than Release 4.9.00086.
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 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
Workarounds
o There are no workarounds that address this vulnerability.
Fixed Software
o 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 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
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 on Cisco.com, do the
following:
1. Click Browse all.
2. Choose Security > VPN and Endpoint Security Clients > Cisco VPN Clients
> AnyConnect Secure Mobility Client > AnyConnect Secure Mobility Client
v4.x.
3. Choose the release from the left pane of the AnyConnect Secure Mobility
Client v4.x page.
Exploitation and Public Announcements
o 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.
The Cisco PSIRT is not aware of any malicious use of the vulnerability that
is described in this advisory.
Source
o Cisco would like to thank Antoine Goichot of PwC Luxembourg's Cybersecurity
team for reporting this vulnerability.
Cisco Security Vulnerability Policy
o To learn about Cisco security vulnerability disclosure policies and
publications, see the Security Vulnerability Policy . This document also
contains instructions for obtaining fixed software and receiving security
vulnerability information from Cisco.
URL
o https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/
cisco-sa-anyconnect-dll-F26WwJW
Revision History
o +---------+---------------------+------------------+--------+-------------+
| Version | Description | Section | Status | Date |
+---------+---------------------+------------------+--------+-------------+
| | Proof-of-concept | Exploitation and | | |
| 1.1 | exploit code is | Public | Final | 2020-AUG-13 |
| | available | Announcements | | |
+---------+---------------------+------------------+--------+-------------+
| 1.0 | Initial public | - | Final | 2020-AUG-05 |
| | release. | | | |
+---------+---------------------+------------------+--------+-------------+
- -----------------------------------------------------------------------------------
Cisco AnyConnect Secure Mobility Client for Windows Denial of Service
Vulnerability
Priority: Medium
Advisory ID: cisco-sa-anyconnect-dos-feXq4tAV
First Published: 2020 August 5 16:00 GMT
Version 1.0: Final
Workarounds: No workarounds availableCisco Bug IDs: CSCvu22424
CVE-2020-3434
CWE-20
Summary
o A vulnerability in the interprocess communication (IPC) channel of Cisco
AnyConnect Secure Mobility Client for Windows could allow an authenticated,
local attacker to cause a denial of service (DoS) condition on an affected
device. To exploit this vulnerability, the attacker would need to have
valid credentials on the Windows system.
The vulnerability is due to insufficient validation of user-supplied input.
An attacker could exploit this vulnerability by sending a crafted IPC
message to the AnyConnect process on an affected device. A successful
exploit could allow the attacker to stop the AnyConnect process, causing a
DoS condition on the device. To exploit this vulnerability, the attacker
would need to have valid credentials on the Windows system.
There are no workarounds that address this vulnerability.
This advisory is available at the following link:
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/
cisco-sa-anyconnect-dos-feXq4tAV
Affected Products
o Vulnerable Products
At the time of publication, this vulnerability affected Cisco AnyConnect
Secure Mobility Client for Windows releases 4.9.00086 and earlier.
See the Details section in the bug ID(s) at the top of this advisory for
the most complete and current information.
Products Confirmed Not Vulnerable
Only products listed in the Vulnerable Products section of this advisory
are known to be affected by this vulnerability.
Workarounds
o There are no workarounds that address this vulnerability.
Fixed Software
o 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
For information about fixed software releases, see the Details section in
the bug ID(s) at the top of this advisory.
Exploitation and Public Announcements
o The Cisco Product Security Incident Response Team (PSIRT) is not aware of
any public announcements or malicious use of the vulnerability that is
described in this advisory.
Source
o Cisco would like to thank Antoine Goichot of PwC Luxembourg's Cybersecurity
team for reporting this vulnerability.
Cisco Security Vulnerability Policy
o To learn about Cisco security vulnerability disclosure policies and
publications, see the Security Vulnerability Policy . This document also
contains instructions for obtaining fixed software and receiving security
vulnerability information from Cisco.
URL
o https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/
cisco-sa-anyconnect-dos-feXq4tAV
Revision History
o +----------+---------------------------+----------+--------+--------------+
| Version | Description | Section | Status | Date |
+----------+---------------------------+----------+--------+--------------+
| 1.0 | Initial public release. | - | Final | 2020-AUG-05 |
+----------+---------------------------+----------+--------+--------------+
- ----------------------------------------------------------------------------------
Cisco AnyConnect Secure Mobility Client for Windows Profile Modification
Vulnerability
Priority: Medium
Advisory ID: cisco-sa-anyconnect-profile-7u3PERKF
First Published: 2020 August 5 16:00 GMT
Version 1.0: Final
Workarounds: No workarounds availableCisco Bug IDs: CSCvu14938
CVE-2020-3435
CWE-20
Summary
o A vulnerability in the interprocess communication (IPC) channel of Cisco
AnyConnect Secure Mobility Client for Windows could allow an authenticated,
local attacker to overwrite VPN profiles on an affected device. To exploit
this vulnerability, the attacker would need to have valid credentials on
the Windows system.
The vulnerability is due to insufficient validation of user-supplied input.
An attacker could exploit this vulnerability by sending a crafted IPC
message to the AnyConnect process on an affected device. A successful
exploit could allow the attacker to modify VPN profile files. To exploit
this vulnerability, the attacker would need to have valid credentials on
the Windows system.
There are no workarounds that address this vulnerability.
This advisory is available at the following link:
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/
cisco-sa-anyconnect-profile-7u3PERKF
Affected Products
o Vulnerable Products
At the time of publication, this vulnerability affected Cisco AnyConnect
Secure Mobility Client for Windows releases 4.9.00086 and earlier.
See the Details section in the bug ID(s) at the top of this advisory for
the most complete and current information.
Products Confirmed Not Vulnerable
Only products listed in the Vulnerable Products section of this advisory
are known to be affected by this vulnerability.
Workarounds
o There are no workarounds that address this vulnerability.
Fixed Software
o 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
For information about fixed software releases, see the Details section in
the bug ID(s) at the top of this advisory.
Exploitation and Public Announcements
o The Cisco Product Security Incident Response Team (PSIRT) is not aware of
any public announcements or malicious use of the vulnerability that is
described in this advisory.
Source
o Cisco would like to thank Antoine Goichot of PwC Luxembourg's Cybersecurity
team for reporting this vulnerability.
Cisco Security Vulnerability Policy
o To learn about Cisco security vulnerability disclosure policies and
publications, see the Security Vulnerability Policy . This document also
contains instructions for obtaining fixed software and receiving security
vulnerability information from Cisco.
URL
o https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/
cisco-sa-anyconnect-profile-7u3PERKF
Revision History
o +----------+---------------------------+----------+--------+--------------+
| Version | Description | Section | Status | Date |
+----------+---------------------------+----------+--------+--------------+
| 1.0 | Initial public release. | - | Final | 2020-AUG-05 |
+----------+---------------------------+----------+--------+--------------+
- --------------------------END INCLUDED TEXT--------------------
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