ID CVE-2004-0847
Summary The Microsoft .NET forms authentication capability for ASP.NET allows remote attackers to bypass authentication for .aspx files in restricted directories via a request containing a (1) "\" (backslash) or (2) "%5C" (encoded backslash), aka "Path Validation Vulnerability."
References
Vulnerable Configurations
  • cpe:2.3:a:microsoft:asp.net:-:*:*:*:*:*:*:*
    cpe:2.3:a:microsoft:asp.net:-:*:*:*:*:*:*:*
  • cpe:2.3:a:microsoft:asp.net:1.0:*:*:*:*:*:*:*
    cpe:2.3:a:microsoft:asp.net:1.0:*:*:*:*:*:*:*
  • cpe:2.3:a:microsoft:asp.net:1.1:*:*:*:*:*:*:*
    cpe:2.3:a:microsoft:asp.net:1.1:*:*:*:*:*:*:*
  • cpe:2.3:a:microsoft:asp.net:1.1:sp1:*:*:*:*:*:*
    cpe:2.3:a:microsoft:asp.net:1.1:sp1:*:*:*:*:*:*
CVSS
Base: 7.5 (as of 12-10-2018 - 21:35)
Impact:
Exploitability:
CWE CWE-22
CAPEC
  • Path Traversal
    An adversary uses path manipulation methods to exploit insufficient input validation of a target to obtain access to data that should be not be retrievable by ordinary well-formed requests. A typical variety of this attack involves specifying a path to a desired file together with dot-dot-slash characters, resulting in the file access API or function traversing out of the intended directory structure and into the root file system. By replacing or modifying the expected path information the access function or API retrieves the file desired by the attacker. These attacks either involve the attacker providing a complete path to a targeted file or using control characters (e.g. path separators (/ or \) and/or dots (.)) to reach desired directories or files.
  • Using Slashes and URL Encoding Combined to Bypass Validation Logic
    This attack targets the encoding of the URL combined with the encoding of the slash characters. An attacker can take advantage of the multiple ways of encoding a URL and abuse the interpretation of the URL. A URL may contain special character that need special syntax handling in order to be interpreted. Special characters are represented using a percentage character followed by two digits representing the octet code of the original character (%HEX-CODE). For instance US-ASCII space character would be represented with %20. This is often referred as escaped ending or percent-encoding. Since the server decodes the URL from the requests, it may restrict the access to some URL paths by validating and filtering out the URL requests it received. An attacker will try to craft an URL with a sequence of special characters which once interpreted by the server will be equivalent to a forbidden URL. It can be difficult to protect against this attack since the URL can contain other format of encoding such as UTF-8 encoding, Unicode-encoding, etc.
  • Manipulating Web Input to File System Calls
    An attacker manipulates inputs to the target software which the target software passes to file system calls in the OS. The goal is to gain access to, and perhaps modify, areas of the file system that the target software did not intend to be accessible.
  • Using Escaped Slashes in Alternate Encoding
    This attack targets the use of the backslash in alternate encoding. An attacker can provide a backslash as a leading character and causes a parser to believe that the next character is special. This is called an escape. By using that trick, the attacker tries to exploit alternate ways to encode the same character which leads to filter problems and opens avenues to attack.
  • Using Slashes in Alternate Encoding
    This attack targets the encoding of the Slash characters. An attacker would try to exploit common filtering problems related to the use of the slashes characters to gain access to resources on the target host. Directory-driven systems, such as file systems and databases, typically use the slash character to indicate traversal between directories or other container components. For murky historical reasons, PCs (and, as a result, Microsoft OSs) choose to use a backslash, whereas the UNIX world typically makes use of the forward slash. The schizophrenic result is that many MS-based systems are required to understand both forms of the slash. This gives the attacker many opportunities to discover and abuse a number of common filtering problems. The goal of this pattern is to discover server software that only applies filters to one version, but not the other.
Access
VectorComplexityAuthentication
NETWORK LOW NONE
Impact
ConfidentialityIntegrityAvailability
PARTIAL PARTIAL PARTIAL
cvss-vector via4 AV:N/AC:L/Au:N/C:P/I:P/A:P
oval via4
  • accepted 2016-02-19T10:00:00.000-04:00
    class vulnerability
    contributors
    • name Matthew Burton
      organization The MITRE Corporation
    • name John Hoyland
      organization Centennial Software
    • name Daniel Tarnu
      organization GFI Software
    • name Jonathan Baker
      organization The MITRE Corporation
    • name Jonathan Baker
      organization The MITRE Corporation
    • name Jeff Cheng
      organization Opsware, Inc.
    • name Jeff Cheng
      organization Opsware, Inc.
    • name Jeff Cheng
      organization Opsware, Inc.
    • name Dragos Prisaca
      organization Secure Elements, Inc.
    • name Nate Przybyszewski
      organization The MITRE Corporation
    • name Maria Mikhno
      organization ALTX-SOFT
    description The Microsoft .NET forms authentication capability for ASP.NET allows remote attackers to bypass authentication for .aspx files in restricted directories via a request containing a (1) "\" (backslash) or (2) "%5C" (encoded backslash), aka "Path Validation Vulnerability."
    family windows
    id oval:org.mitre.oval:def:3556
    status accepted
    submitted 2005-03-31T12:00:00.000-04:00
    title Microsoft .NET Framework v1.1 Security Bypass
    version 32
  • accepted 2008-02-25T04:00:09.634-05:00
    class vulnerability
    contributors
    • name Matthew Burton
      organization The MITRE Corporation
    • name John Hoyland
      organization Centennial Software
    • name Matthew Wojcik
      organization The MITRE Corporation
    • name Daniel Tarnu
      organization GFI Software
    • name Robert L. Hollis
      organization ThreatGuard, Inc.
    • name Jeff Cheng
      organization Opsware, Inc.
    • name Jeff Cheng
      organization Opsware, Inc.
    • name Jeff Cheng
      organization Hewlett-Packard
    description The Microsoft .NET forms authentication capability for ASP.NET allows remote attackers to bypass authentication for .aspx files in restricted directories via a request containing a (1) "\" (backslash) or (2) "%5C" (encoded backslash), aka "Path Validation Vulnerability."
    family windows
    id oval:org.mitre.oval:def:4987
    status accepted
    submitted 2005-03-31T12:00:00.000-04:00
    title Microsoft .NET Framework v1.0 Security Bypass
    version 29
refmap via4
bid 11342
cert TA05-039A
cert-vn VU#283646
misc http://sourceforge.net/mailarchive/forum.php?thread_id=5671607&forum_id=24754
ms MS05-004
ntbugtraq 20040914 Security bug in .NET Forms Authentication
xf windows-forms-security-bypass(17644)
Last major update 12-10-2018 - 21:35
Published 03-11-2004 - 05:00
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