Improper Handling of Case SensitivityID: 178 | Date: (C)2012-05-14 (M)2022-10-10 |
Type: weakness | Status: INCOMPLETE |
Abstraction Type: Base |
Description
The software does not properly account for differences in case
sensitivity when accessing or determining the properties of a resource, leading
to inconsistent results.
Extended DescriptionImproperly handled case sensitive data can lead to several possible
consequences, including:case-insensitive passwords reducing the size of the key space, making
brute force attacks easierbypassing filters or access controls using alternate namesmultiple interpretation errors using alternate names.
Applicable PlatformsLanguage Class: All
Time Of Introduction
Common Consequences
Scope | Technical Impact | Notes |
---|
Access_Control | Bypass protection
mechanism | |
Detection MethodsNone
Potential Mitigations
Phase | Strategy | Description | Effectiveness | Notes |
---|
Architecture and Design | Input Validation | Avoid making decisions based on names of resources (e.g. files) if
those resources can have alternate names. | | |
Implementation | Input Validation | Assume all input is malicious. Use an "accept known good" input
validation strategy, i.e., use a whitelist of acceptable inputs that
strictly conform to specifications. Reject any input that does not
strictly conform to specifications, or transform it into something that
does.When performing input validation, consider all potentially relevant
properties, including length, type of input, the full range of
acceptable values, missing or extra inputs, syntax, consistency across
related fields, and conformance to business rules. As an example of
business rule logic, "boat" may be syntactically valid because it only
contains alphanumeric characters, but it is not valid if the input is
only expected to contain colors such as "red" or "blue."Do not rely exclusively on looking for malicious or malformed inputs
(i.e., do not rely on a blacklist). A blacklist is likely to miss at
least one undesirable input, especially if the code's environment
changes. This can give attackers enough room to bypass the intended
validation. However, blacklists can be useful for detecting potential
attacks or determining which inputs are so malformed that they should be
rejected outright. | | |
Implementation | Input Validation | Inputs should be decoded and canonicalized to the application's
current internal representation before being validated (CWE-180). Make
sure that the application does not decode the same input twice
(CWE-174). Such errors could be used to bypass whitelist validation
schemes by introducing dangerous inputs after they have been
checked. | | |
Relationships
Related CWE | Type | View | Chain |
---|
CWE-178 ChildOf CWE-896 | Category | CWE-888 | |
Demonstrative Examples (Details)
- In the following example, an XSS neutralization method replaces
script tags in user supplied input with a safe equivalent:
Observed Examples
- CVE-2000-0499 : Application server allows attackers to bypass execution of a jsp page and read the source code using an upper case JSP extension in the request.
- CVE-2000-0497 : The server is case sensitive, so filetype handlers treat .jsp and .JSP as different extensions. JSP source code may be read because .JSP defaults to the filetype "text".
- CVE-2000-0498 : The server is case sensitive, so filetype handlers treat .jsp and .JSP as different extensions. JSP source code may be read because .JSP defaults to the filetype "text".
- CVE-2001-0766 : A URL that contains some characters whose case is not matched by the server's filters may bypass access restrictions because the case-insensitive file system will then handle the request after it bypasses the case sensitive filter.
- CVE-2001-0795 : Server allows remote attackers to obtain source code of CGI scripts via URLs that contain MS-DOS conventions such as (1) upper case letters or (2) 8.3 file names.
- CVE-2001-1238 : Task Manager does not allow local users to end processes with uppercase letters named (1) winlogon.exe, (2) csrss.exe, (3) smss.exe and (4) services.exe via the Process tab which could allow local users to install Trojan horses that cannot be stopped.
- CVE-2003-0411 : chain: Code was ported from a case-sensitive Unix platform to a case-insensitive Windows platform where filetype handlers treat .jsp and .JSP as different extensions. JSP source code may be read because .JSP defaults to the filetype "text".
- CVE-2002-0485 : Leads to interpretation error
- CVE-1999-0239 : Directories may be listed because lower case web requests are not properly handled by the server.
- CVE-2005-0269 : File extension check in forum software only verifies extensions that contain all lowercase letters, which allows remote attackers to upload arbitrary files via file extensions that include uppercase letters.
- CVE-2004-1083 : Web server restricts access to files in a case sensitive manner, but the filesystem accesses files in a case insensitive manner, which allows remote attackers to read privileged files using alternate capitalization.
- CVE-2002-2119 : Case insensitive passwords lead to search space reduction.
- CVE-2004-2214 : HTTP server allows bypass of access restrictions using URIs with mixed case.
- CVE-2004-2154 : Mixed upper/lowercase allows bypass of ACLs.
- CVE-2005-4509 : Bypass malicious script detection by using tokens that aren't case sensitive.
- CVE-2002-1820 : Mixed case problem allows "admin" to have "Admin" rights (alternate name property).
- CVE-2007-3365 : Chain: uppercase file extensions causes web server to return script source code instead of executing the script.
For more examples, refer to CVE relations in the bottom box.
White Box Definitions None
Black Box Definitions None
Taxynomy Mappings
Taxynomy | Id | Name | Fit |
---|
PLOVER | | Case Sensitivity (lowercase, uppercase, mixed
case) | |
References:None