Microsoft Windows XP TCP Packet Information Leakage Vulnerability
BID:8531
Info
Microsoft Windows XP TCP Packet Information Leakage Vulnerability
| Bugtraq ID: | 8531 |
| Class: | Design Error |
| CVE: | |
| Remote: | Yes |
| Local: | No |
| Published: | Sep 02 2003 12:00AM |
| Updated: | Sep 02 2003 12:00AM |
| Credit: | The discovery of this vulnerability has been credited to Michal Zalewski. |
| Vulnerable: |
Microsoft Windows XP Professional SP1 Microsoft Windows XP Professional Microsoft Windows XP Media Center Edition Microsoft Windows XP Home SP1 Microsoft Windows XP Home |
| Not Vulnerable: | |
Discussion
Microsoft Windows XP TCP Packet Information Leakage Vulnerability
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.
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.
Exploit / POC
Microsoft Windows XP TCP Packet Information Leakage Vulnerability
The following packet capture, which demonstrates this lack of URG flag initialization, has been supplied by Michal Zalewski.
<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
The following packet capture, which demonstrates this lack of URG flag initialization, has been supplied by Michal Zalewski.
<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
Solution / Fix
Microsoft Windows XP TCP Packet Information Leakage Vulnerability
Solution:
Currently we are not aware of any vendor-supplied patches for this issue. If you feel we are in error or are aware of more recent information, please mail us at: [email protected] <mailto:[email protected]>.
Solution:
Currently we are not aware of any vendor-supplied patches for this issue. If you feel we are in error or are aware of more recent information, please mail us at: [email protected] <mailto:[email protected]>.