Information leaks in IIS 4 through 5.1 allow remote attackers to obtain potentially sensitive information or more easily conduct brute force attacks via responses from the server in which (2) in certain configurations, the server IP address is provided as the realm for Basic authentication, which could reveal real IP addresses that were obscured by NAT, or (3) when NTLM authentication is used, the NetBIOS name of the server and its Windows NT domain are revealed in response to an Authorization request. NOTE: this entry originally contained a vector (1) in which the server reveals whether it supports Basic or NTLM authentication through 401 Access Denied error messages. CVE has REJECTED this vector; it is not a vulnerability because the information is already available through legitimate use, since authentication cannot proceed without specifying a scheme that is supported by both the client and the server.
The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Internet_information_server | Microsoft | 4.0 (including) | 4.0 (including) |
| Internet_information_server | Microsoft | 4.0-alpha (including) | 4.0-alpha (including) |
| Internet_information_services | Microsoft | 5.0 (including) | 5.0 (including) |
There are many different kinds of mistakes that introduce information exposures. The severity of the error can range widely, depending on the context in which the product operates, the type of sensitive information that is revealed, and the benefits it may provide to an attacker. Some kinds of sensitive information include:
Information might be sensitive to different parties, each of which may have their own expectations for whether the information should be protected. These parties include:
Information exposures can occur in different ways:
It is common practice to describe any loss of confidentiality as an “information exposure,” but this can lead to overuse of CWE-200 in CWE mapping. From the CWE perspective, loss of confidentiality is a technical impact that can arise from dozens of different weaknesses, such as insecure file permissions or out-of-bounds read. CWE-200 and its lower-level descendants are intended to cover the mistakes that occur in behaviors that explicitly manage, store, transfer, or cleanse sensitive information.