Rule

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Sid:
995


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Summary:
This event is generated when an attempt is made to request an HTTP-based password change.

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Impact:
Information gathering/remote access.  Error messages from failed password changes can indicate whether a given account exists on the server.  Successful password changes can allow remote access to the server. 

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Detailed Information:
Microsoft Internet Information Services (IIS) Version 4 servers that were upgraded from IIS 2 or 3 have a legacy ism.dll file that allows web-based administration.  Upon sending a request to ism.dll, the user will be prompted for a userid and password.  An attacker can attempt to brute force guess a password, allowing remote access to the server.

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Affected Systems:

Microsoft IIS 4.0 servers upgraded from IIS 2.0 or 3.0

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Attack Scenarios:
An attacker can request password changes to discover existing accounts or brute force password changes.

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Ease of Attack:
Simple.

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False Positives:
None Known.

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False Negatives:
None Known.

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Corrective Action:
Upgrade to a more current version of ISS.

Consider running the IIS Lockdown Tool to disable unnecessary functionality.

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Contributors:
Original rule writer unknown
Modified by Brian Caswell <bmc@sourcefire.com>
Sourcefire Vulnerability Research Team
Judy Novak <judy.novak@sourcefire.com>

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Additional References:

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