source: http://www.securityfocus.com/bid/8531/info

A vulnerability has been discovered in Microsoft Windows XP that could result in the contents of memory being disclosed within some TCP packets. The problem specifically occurs within some SYN packets transmitted by Windows XP, which may not have correctly zeroed out URG flags. These flags may in fact contain data leaked from previously used memory. By continuously observing these abnormal SYN packets, it may be possible for an attacker to obtain sensitive information. 

<Tue Sep 2 13:02:48 2003> A:3827 - Windows XP (2) (PLEASE REPORT!) [GENERIC]
Signature: [16384:119:1:48:M1460,N,N,S:U:Windows:?]
-> server:80 (distance 9, link: ethernet/modem)
-- EXTRA TCP VALUES: ACK=0x0, UNUSED=0, URG=0x819e

<Tue Sep 2 13:02:48 2003> A:3829 - Windows XP (2) (PLEASE REPORT!) [GENERIC]
Signature: [16384:119:1:48:M1460,N,N,S:U:Windows:?]
-> server:80 (distance 9, link: ethernet/modem)
-- EXTRA TCP VALUES: ACK=0x0, UNUSED=0, URG=0xdc19

<Tue Sep 2 13:02:49 2003> A:3830 - Windows XP (2) (PLEASE REPORT!) [GENERIC]
Signature: [16384:119:1:48:M1460,N,N,S:U:Windows:?]
-> server:80 (distance 9, link: ethernet/modem)
-- EXTRA TCP VALUES: ACK=0x0, UNUSED=0, URG=0x8158

<Tue Sep 2 13:02:49 2003> A:3833 - Windows XP (2) (PLEASE REPORT!) [GENERIC]
Signature: [16384:119:1:48:M1460,N,N,S:U:Windows:?]
-> server:80 (distance 9, link: ethernet/modem)
-- EXTRA TCP VALUES: ACK=0x0, UNUSED=0, URG=0x8158