{"@ID": "181", "@Name": "Incorrect Behavior Order: Validate Before Filter", "@Abstraction": "Variant", "@Structure": "Simple", "@Status": "Draft", "Description": "The product validates data before it has been filtered, which prevents the product from detecting data that becomes invalid after the filtering step.", "Related_Weaknesses": {"Related_Weakness": {"@Nature": "ChildOf", "@CWE_ID": "179", "@View_ID": "1000", "@Ordinal": "Primary"}}, "Weakness_Ordinalities": {"Weakness_Ordinality": {"Ordinality": "Primary"}}, "Applicable_Platforms": {"Language": {"@Class": "Not Language-Specific", "@Prevalence": "Undetermined"}}, "Alternate_Terms": {"Alternate_Term": {"Term": "Validate-before-cleanse"}}, "Modes_Of_Introduction": {"Introduction": {"Phase": "Implementation"}}, "Common_Consequences": {"Consequence": {"Scope": "Access Control", "Impact": "Bypass Protection Mechanism", "Note": "This prevents the product from detecting data\n\t       that becomes invalid after the filtering step. An\n\t       attacker can bypass the validation and launch attacks\n\t       that expose weaknesses that would otherwise be\n\t       prevented, such as injection."}}, "Potential_Mitigations": {"Mitigation": {"Phase": ["Implementation", "Architecture and Design"], "Description": "Inputs should be decoded and canonicalized to the application's current internal representation before being filtered."}}, "Demonstrative_Examples": {"Demonstrative_Example": {"@Demonstrative_Example_ID": "DX-36", "Intro_Text": "This script creates a subdirectory within a user directory and sets the user as the owner.", "Example_Code": {"@Nature": "Bad", "@Language": "PHP", "xhtml:div": {"xhtml:div": {"@style": "margin-left:1em;", "xhtml:br": [null, null, null, null, null, null], "xhtml:div": {"@style": "margin-left:1em;", "xhtml:br": null, "#text": "echo 'Directory name contains invalid sequence';return;"}, "xhtml:i": "//filter out '~' because other scripts identify user directories by this prefix", "#text": "$userDir = '/users/'. $userName;if(strpos($dirName,'..') !== false){}\n                        \n                        $dirName = str_replace('~','',$dirName);$newDir = $userDir . $dirName;mkdir($newDir, 0700);chown($newDir,$userName);"}, "#text": "function createDir($userName,$dirName){}"}, "#text_blocks": ["function createDir($userName,$dirName){", "$userDir = '/users/'. $userName;", "if(strpos($dirName,'..') !== false){", "echo 'Directory name contains invalid sequence';", "return;", "}", "//filter out '~' because other scripts identify user directories by this prefix", "$dirName = str_replace('~','',$dirName);", "$newDir = $userDir . $dirName;", "mkdir($newDir, 0700);", "chown($newDir,$userName);", "}"]}, "Body_Text": "While the script attempts to screen for '..' sequences, an attacker can submit a directory path including \".~.\", which will then become \"..\" after the filtering step. This allows a Path Traversal (CWE-21) attack to occur."}}, "Observed_Examples": {"Observed_Example": [{"Reference": "CVE-2002-0934", "Description": "Directory traversal vulnerability allows remote attackers to read or modify arbitrary files via invalid characters between two . (dot) characters, which are filtered and result in a \"..\" sequence.", "Link": "https://www.cve.org/CVERecord?id=CVE-2002-0934"}, {"Reference": "CVE-2003-0282", "Description": "Directory traversal vulnerability allows attackers to overwrite arbitrary files via invalid characters between two . (dot) characters, which are filtered and result in a \"..\" sequence.", "Link": "https://www.cve.org/CVERecord?id=CVE-2003-0282"}]}, "Functional_Areas": {"Functional_Area": "Protection Mechanism"}, "Taxonomy_Mappings": {"Taxonomy_Mapping": [{"@Taxonomy_Name": "PLOVER", "Entry_Name": "Validate-Before-Filter"}, {"@Taxonomy_Name": "OWASP Top Ten 2004", "Entry_ID": "A1", "Entry_Name": "Unvalidated Input", "Mapping_Fit": "CWE More Specific"}]}, "Related_Attack_Patterns": {"Related_Attack_Pattern": [{"@CAPEC_ID": "120"}, {"@CAPEC_ID": "267"}, {"@CAPEC_ID": "3"}, {"@CAPEC_ID": "43"}, {"@CAPEC_ID": "78"}, {"@CAPEC_ID": "79"}, {"@CAPEC_ID": "80"}]}, "Mapping_Notes": {"Usage": "Allowed", "Rationale": "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.", "Comments": "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.", "Reasons": {"Reason": {"@Type": "Acceptable-Use"}}}, "Notes": {"Note": {"@Type": "Research Gap", "#text": "This category is probably under-studied."}}, "Content_History": {"Submission": {"Submission_Name": "PLOVER", "Submission_Date": "2006-07-19", "Submission_Version": "Draft 3", "Submission_ReleaseDate": "2006-07-19"}, "Modification": [{"Modification_Name": "Eric Dalci", "Modification_Organization": "Cigital", "Modification_Date": "2008-07-01", "Modification_Version": "1.0", "Modification_ReleaseDate": "2008-09-09", "Modification_Comment": "updated Potential_Mitigations, Time_of_Introduction"}, {"Modification_Organization": "Veracode", "Modification_Date": "2008-08-15", "Modification_Version": "1.0", "Modification_ReleaseDate": "2008-09-09", "Modification_Comment": "Suggested OWASP Top Ten 2004 mapping"}, {"Modification_Name": "CWE Content Team", "Modification_Organization": "MITRE", "Modification_Date": "2008-09-08", "Modification_Version": "1.0", "Modification_ReleaseDate": "2008-09-09", "Modification_Comment": "updated Functional_Areas, Relationships, Research_Gaps, Taxonomy_Mappings, Type"}, {"Modification_Name": "CWE Content Team", "Modification_Organization": "MITRE", "Modification_Date": "2008-10-14", "Modification_Version": "1.0.1", "Modification_ReleaseDate": "2008-10-14", "Modification_Comment": "updated Description"}, {"Modification_Name": "CWE Content Team", "Modification_Organization": "MITRE", "Modification_Date": "2010-06-21", "Modification_Version": "1.9", "Modification_ReleaseDate": "2010-06-21", "Modification_Comment": "updated Description, Observed_Examples"}, {"Modification_Name": "CWE Content Team", "Modification_Organization": "MITRE", "Modification_Date": "2011-03-29", "Modification_Version": "1.12", "Modification_ReleaseDate": "2011-03-30", "Modification_Comment": "updated Demonstrative_Examples"}, {"Modification_Name": "CWE Content Team", "Modification_Organization": "MITRE", "Modification_Date": "2011-06-01", "Modification_Version": "1.13", "Modification_ReleaseDate": "2011-06-01", "Modification_Comment": "updated Common_Consequences"}, {"Modification_Name": "CWE Content Team", "Modification_Organization": "MITRE", "Modification_Date": "2012-05-11", "Modification_Version": "2.2", "Modification_ReleaseDate": "2012-05-15", "Modification_Comment": "updated Demonstrative_Examples, Observed_Examples, Related_Attack_Patterns, Relationships"}, {"Modification_Name": "CWE Content Team", "Modification_Organization": "MITRE", "Modification_Date": "2012-10-30", "Modification_Version": "2.3", "Modification_ReleaseDate": "2012-10-30", "Modification_Comment": "updated Potential_Mitigations"}, {"Modification_Name": "CWE Content Team", "Modification_Organization": "MITRE", "Modification_Date": "2014-07-30", "Modification_Version": "2.8", "Modification_ReleaseDate": "2014-07-31", "Modification_Comment": "updated Relationships"}, {"Modification_Name": "CWE Content Team", "Modification_Organization": "MITRE", "Modification_Date": "2017-01-19", "Modification_Version": "2.10", "Modification_ReleaseDate": "2017-01-19", "Modification_Comment": "updated Relationships"}, {"Modification_Name": "CWE Content Team", "Modification_Organization": "MITRE", "Modification_Date": "2017-11-08", "Modification_Version": "3.0", "Modification_ReleaseDate": "2017-11-08", "Modification_Comment": "updated Applicable_Platforms"}, {"Modification_Name": "CWE Content Team", "Modification_Organization": "MITRE", "Modification_Date": "2019-01-03", "Modification_Version": "3.2", "Modification_ReleaseDate": "2019-01-03", "Modification_Comment": "updated Related_Attack_Patterns"}, {"Modification_Name": "CWE Content Team", "Modification_Organization": "MITRE", "Modification_Date": "2020-02-24", "Modification_Version": "4.0", "Modification_ReleaseDate": "2020-02-24", "Modification_Comment": "updated Relationships, Type"}, {"Modification_Name": "CWE Content Team", "Modification_Organization": "MITRE", "Modification_Date": "2023-01-31", "Modification_Version": "4.10", "Modification_ReleaseDate": "2023-01-31", "Modification_Comment": "updated Description"}, {"Modification_Name": "CWE Content Team", "Modification_Organization": "MITRE", "Modification_Date": "2023-04-27", "Modification_Version": "4.11", "Modification_ReleaseDate": "2023-04-27", "Modification_Comment": "updated Relationships"}, {"Modification_Name": "CWE Content Team", "Modification_Organization": "MITRE", "Modification_Date": "2023-06-29", "Modification_Version": "4.12", "Modification_ReleaseDate": "2023-06-29", "Modification_Comment": "updated Mapping_Notes"}, {"Modification_Name": "CWE Content Team", "Modification_Organization": "MITRE", "Modification_Date": "2025-12-11", "Modification_Version": "4.19", "Modification_ReleaseDate": "2025-12-11", "Modification_Comment": "updated Weakness_Ordinalities"}, {"Modification_Name": "CWE Content Team", "Modification_Organization": "MITRE", "Modification_Date": "2026-10-28", "Modification_Version": "5.0", "Modification_ReleaseDate": "2026-10-28", "Modification_Comment": "updated Common_Consequences, Description"}], "Previous_Entry_Name": {"@Date": "2008-04-11", "#text": "Validate-before-filter"}}, "entry_type": "Weakness"}