Vigil@nce: Citrix Online Plug-in, ICA Client, spoofing of X.509 certificate
November 2009 by Vigil@nce
An attacker can setup a server with a malicious X.509 certificate, in order to deceive victims connecting with Citrix Online Plug-in or an ICA Client.
Consequences: user access/rights, data reading, data creation/edition
Provenance: internet server
Means of attack: no proof of concept, no attack
Ability of attacker: expert (4/4)
Confidence: confirmed by the editor (5/5)
Diffusion of the vulnerable configuration: high (3/3)
Creation date: 12/11/2009
DESCRIPTION OF THE VULNERABILITY
The Citrix Online Plug-in (ICA Client) products are used to connect to XenApp and XenDesktop. The ICA (Independent Computing Architecture) stream can be secured via a SSL/TLS session.
However, clients do not check if the X.509 certificate offered by the server is valid, before accepting the session.
An attacker can therefore setup a server with a malicious X.509 certificate, in order to deceive victims connecting with Citrix Online Plug-in or an ICA Client.
This vulnerability seems to be similar to VIGILANCE-VUL-8908 (https://vigilance.fr/tree/1/8908), but this is unconfirmed.