Description of Problem
A vulnerability has been identified in the Citrix Online Plug-ins and ICA clients that could result in arbitrary code being executed in the context of the logged in user.
If a user can be lured into invoking an ICA connection to a server controlled by the attacker, it may be possible for the attacker to execute arbitrary code on the client device in the context of the logged in user.
ICA connections can be invoked by launching an .ICA file or by using an ICA client browser plug-in. For example, this could occur if a user visits an untrusted website or opens an untrusted e-mail attachment.
What Customers Should Do
Citrix has released updated versions of its Online Plug-ins and ICA clients to address this issue, and strongly recommends that customers install the latest versions of the following clients:
Citrix Online Plug-in for Windows for XenApp & XenDesktop:
This issue has been resolved in version 11.2 and later. However, due to the vulnerability described in CTX125976 - Vulnerability in Citrix XenApp Online Plug-in for Windows Could Result in Arbitrary Code Execution, Citrix recommends that customers upgrade to the latest version of this client, which is available at the following location:
Attempts to launch links from the Web Sites and File Shares panes of the Access interface of Access Gateway Advanced Edition can fail with Version 12.x of the Citrix Online Plug-in. This is caused by a known compatibility issue between these components. An update to the plug-in addressing this issue is available, customers using such a deployment should contact their Support representative for additional guidance and reference fix numbers 236847 and 240207.
Citrix Online Plug-in for Mac for XenApp & XenDesktop:
This issue has been resolved in version 11.0 and later. The latest version of this client is available from the following location:
Citrix ICA Client for Linux (x86 and ARM):
This issue has been resolved in version 11.100 and later. The latest version of this client is available from the following location:
Citrix ICA Client for Solaris (x86 and Sparc):
This issue has been resolved in version 8.63 and later. The latest version of this client is available from the following location:
Citrix Receiver for Windows Mobile:
This issue has been resolved in version 11.5 and later. The latest version of this client is available from the following location:
The ICA client for Java, the Citrix Receiver for iPhone/iPad, and the Citrix Receiver for Android are not affected by this vulnerability. Customers using client versions not mentioned in this document should contact their support representative for further guidance.
Citrix thanks Michael Jordon of Context Information Security Ltd. (http://www.contextis.co.uk/) for working with us to protect Citrix customers
What Citrix Is Doing
Citrix is notifying customers and channel partners about this potential security issue. This article is also available from the Citrix Knowledge Center at http://support.citrix.com/.
Obtaining Support on This Issue
If you require technical assistance with this issue, please contact Citrix Technical Support. Contact details for Citrix Technical Support are available at http://www.citrix.com/site/ss/supportContacts.asp.
Reporting Security Vulnerabilities to Citrix
Citrix welcomes input regarding the security of its products and considers any and all potential vulnerabilities seriously. If you would like to report a security issue to Citrix, please compose an e-mail to email@example.com stating the exact version of the product in which the vulnerability was found and the steps needed to reproduce the vulnerability