ZDI-07-053: Microsoft ISA Server SOCKS4 Proxy Connection Leakage

http://www.zerodayinitiative.com/advisories/ZDI-07-053.html

September 20, 2007

-- CVE ID:

CVE-2007-4991

-- Affected Vendor:

Microsoft

-- Affected Products:

ISA Server 2004 SP1

ISA Server 2004 SP2

-- TippingPoint(TM) IPS Customer Protection:

TippingPoint IPS customers have been protected against this

vulnerability since September 20, 2007 by Digital Vaccine protection

filter ID 4085. For further product information on the TippingPoint IPS:

http://www.tippingpoint.com

-- Vulnerability Details:

This vulnerability allows remote attackers to extract IP addresses

visited through the SOCKS4 Proxy on vulnerable ISA Server

installations. Authentication is not required to exploit this

vulnerability.

This specific flaw exists when an empty packet is sent to the SOCKS4.

The server will return a packet containing the last IP address it

proxied to.

-- Vendor Response:

Microsoft has issued an update to correct this vulnerability. More

details can be found at:

http://www.microsoft.com/downloads/details.aspx?FamilyID=A05A074A-5033-4
792-AF8B-58B90D841436&displaylang=en

-- Disclosure Timeline:

2006.01.30 - Vulnerability reported to vendor

2007.09.20 - Digital Vaccine released to TippingPoint customers

2007.09.20 - Coordinated public release of advisory

-- Credit:

This vulnerability was discovered by CIRT.DK.

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