The product contains protection mechanisms to restrict access to 'realdir/filename', but it constructs pathnames using external input in the form of 'fakedir/../realdir/filename' that are not handled by those mechanisms. This allows attackers to perform unauthorized actions against the targeted file.

Resultant

Implementation

Confidentiality
Integrity
Read Files or Directories
Modify Files or Directories

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

CVE-2001-1152
Proxy allows remote attackers to bypass denylist restrictions and connect to unauthorized web servers by modifying the requested URL, including (1) a // (double slash), (2) a /SUBDIR/.. where the desired file is in the parentdir, (3) a /./, or (4) URL-encoded characters.
https://www.cve.org/CVERecord?id=CVE-2001-1152

CVE-2000-0191
application check access for restricted URL before canonicalization
https://www.cve.org/CVERecord?id=CVE-2000-0191

CVE-2005-1366
CGI source disclosure using "dirname/../cgi-bin"
https://www.cve.org/CVERecord?id=CVE-2005-1366

File Processing

File or Directory

dirname/fakechild/../realchild/filename

SFP16
Path Traversal

Allowed
This CWE entry is at the Variant level of abstraction, which is a preferred level of abstraction for mapping to the root causes of vulnerabilities.
Carefully read both the name and description to ensure that this mapping is an appropriate fit. Do not try to 'force' a mapping to a lower-level Base/Variant simply to comply with this preferred level of abstraction.

This is a manipulation that uses an injection for one consequence (containment violation using relative path) to achieve a different consequence (equivalence by alternate name).

PLOVER
2006-07-19
Draft 3
2006-07-19

Eric Dalci
Cigital
2008-07-01
updated Time_of_Introduction

CWE Content Team
MITRE
2008-09-08
updated Relationships, Other_Notes, Taxonomy_Mappings

CWE Content Team
MITRE
2008-10-14
updated Description, Name, Observed_Examples, Other_Notes, Theoretical_Notes

CWE Content Team
MITRE
2011-06-01
updated Common_Consequences

CWE Content Team
MITRE
2012-05-11
updated Observed_Examples, Relationships

CWE Content Team
MITRE
2012-10-30
updated Potential_Mitigations

CWE Content Team
MITRE
2014-07-30
updated Relationships, Taxonomy_Mappings

CWE Content Team
MITRE
2017-11-08
updated Applicable_Platforms

CWE Content Team
MITRE
2020-02-24
updated Relationships

CWE Content Team
MITRE
2020-06-25
updated Observed_Examples, Potential_Mitigations

CWE Content Team
MITRE
2023-01-31
updated Description

CWE Content Team
MITRE
2023-04-27
updated Relationships

CWE Content Team
MITRE
2023-06-29
updated Mapping_Notes

CWE Content Team
MITRE
2025-09-09
4.18
2025-09-09
updated Affected_Resources, Functional_Areas

CWE Content Team
MITRE
2025-12-11
4.19
2025-12-11
updated Applicable_Platforms, Weakness_Ordinalities

Path Issue - dirname/fakechild/../realchild/filename
Path Equivalence: 'dirname/fakechild/../realchild/filename'