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Citrix Presentation Server Client ActiveX Heap Overflow Vulnerability

TPTI-06-15: December 6th, 2006

CVE ID

Affected Vendors

Affected Products

TippingPoint™ IPS Customer Protection

TippingPoint IPS customers are protected against this vulnerability by Digital Vaccine protection filter ID 4163. For further product information on the TippingPoint IPS:

Vulnerability Details

This vulnerability allows attackers to execute arbitrary code on vulnerable installations of Citrix Presentation Server Client for Windows. User interaction is required to exploit this vulnerability in that the target must visit a malicious page.

The specific flaw resides in the SendChannelData function of the ActiveX control Wfica.ocx (CLSID 238F6F83-B8B4-11CF-8771-00A024541EE3). The function is prototyped as follows:

SendChannelData(ChannelName As String,
Data As String,
DataSize As Long,
DataType As ICAVCDataType)

Specifying an undersized buffer length as the 'DataSize' parameter and supplying a large buffer as the 'Data' parameter results in an exploitable heap corruption.

Vendor Response

Citrix has issued an update to correct this vulnerability. More details can be found at:

Disclosure Timeline

    2006-09-19 - Vulnerability reported to vendor
    2006-12-06 - Coordinated public release of advisory

Credit

This vulnerability was discovered by: