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.

Modes of Introduction:

– Implementation

Related Weaknesses

CWE-706
CWE-706
CWE-433
CWE-289

Consequences

Access Control: Bypass Protection Mechanism

Potential Mitigations

Phase: Architecture and Design

Description: 

Avoid making decisions based on names of resources (e.g. files) if those resources can have alternate names.

Phase: Implementation

Description: 

Phase: Implementation

Description: 

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 allowlist validation schemes by introducing dangerous inputs after they have been checked.

CVE References

• 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.