CVE-2009-0085 - Improper Authentication

Severity

71%

Complexity

86%

Confidentiality

115%

The Secure Channel (aka SChannel) authentication component in Microsoft Windows 2000 SP4, XP SP2 and SP3, Server 2003 SP1 and SP2, Vista Gold and SP1, and Server 2008, when certificate authentication is used, does not properly validate the client's key exchange data in Transport Layer Security (TLS) handshake messages, which allows remote attackers to spoof authentication by crafting a TLS packet based on knowledge of the certificate but not the private key, aka "SChannel Spoofing Vulnerability."

The Secure Channel (aka SChannel) authentication component in Microsoft Windows 2000 SP4, XP SP2 and SP3, Server 2003 SP1 and SP2, Vista Gold and SP1, and Server 2008, when certificate authentication is used, does not properly validate the client's key exchange data in Transport Layer Security (TLS) handshake messages, which allows remote attackers to spoof authentication by crafting a TLS packet based on knowledge of the certificate but not the private key, aka "SChannel Spoofing Vulnerability."

CVSS 2.0 Base Score 7.1. CVSS Attack Vector: network. CVSS Attack Complexity: medium. CVSS Vector: (AV:N/AC:M/Au:N/C:N/I:C/A:N).

Demo Examples

Improper Authentication

CWE-287

The following code intends to ensure that the user is already logged in. If not, the code performs authentication with the user-provided username and password. If successful, it sets the loggedin and user cookies to "remember" that the user has already logged in. Finally, the code performs administrator tasks if the logged-in user has the "Administrator" username, as recorded in the user cookie.


               
}
}
ExitError("Error: you need to log in first");
);
);
DoAdministratorTasks();

Unfortunately, this code can be bypassed. The attacker can set the cookies independently so that the code does not check the username and password. The attacker could do this with an HTTP request containing headers such as:


               
[body of request]

By setting the loggedin cookie to "true", the attacker bypasses the entire authentication check. By using the "Administrator" value in the user cookie, the attacker also gains privileges to administer the software.

Improper Authentication

CWE-287

Overview

Type

Microsoft Windows

First reported 15 years ago

2009-03-10 20:30:00

Last updated 5 years ago

2019-02-26 14:04:00

Affected Software

Microsoft Windows 2000 Service Pack 4

Microsoft Windows Server 2003

Microsoft Windows Server 2003 Service Pack 2

Microsoft Windows Server 2008

Microsoft Windows Server 2008 Itanium

Microsoft Windows Server 2008 x64 (64-bit) (intial release)

Microsoft Windows Vista x64 (64-bit)

Microsoft Windows Vista Service Pack 1 (initial release)

Microsoft Windows Vista Service Pack 1 x64 (64-bit)

Microsoft Windows XP 64-bit

Microsoft Windows XP Service Pack 2

Microsoft Windows XP Service Pack 2 x64 (64-bit)

Microsoft Windows XP Service Pack 3

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