{"@ID": "396", "@Name": "Declaration of Catch for Generic Exception", "@Abstraction": "Base", "@Structure": "Simple", "@Status": "Draft", "Description": "Catching overly broad exceptions promotes complex error handling code that is more likely to contain security vulnerabilities.", "Extended_Description": "Multiple catch blocks can get ugly and repetitive, but \"condensing\" catch blocks by catching a high-level class like Exception can obscure exceptions that deserve special treatment or that should not be caught at this point in the program. Catching an overly broad exception essentially defeats the purpose of a language's typed exceptions, and can become particularly dangerous if the program grows and begins to throw new types of exceptions. The new exception types will not receive any attention.", "Related_Weaknesses": {"Related_Weakness": [{"@Nature": "ChildOf", "@CWE_ID": "705", "@View_ID": "1000", "@Ordinal": "Primary"}, {"@Nature": "ChildOf", "@CWE_ID": "755", "@View_ID": "1000"}, {"@Nature": "ChildOf", "@CWE_ID": "221", "@View_ID": "1000"}]}, "Weakness_Ordinalities": {"Weakness_Ordinality": {"Ordinality": "Primary"}}, "Applicable_Platforms": {"Language": [{"@Name": "C++", "@Prevalence": "Undetermined"}, {"@Name": "Java", "@Prevalence": "Undetermined"}, {"@Name": "C#", "@Prevalence": "Undetermined"}, {"@Name": "Python", "@Prevalence": "Undetermined"}]}, "Modes_Of_Introduction": {"Introduction": {"Phase": "Implementation"}}, "Common_Consequences": {"Consequence": {"Scope": ["Non-Repudiation", "Other"], "Impact": "Hide Activities", "Note": "A generic exception can hide details about unexpected adversary activities by making it difficult to properly troubleshoot error conditions during execution."}}, "Detection_Methods": {"Detection_Method": {"@Detection_Method_ID": "DM-14", "Method": "Automated Static Analysis", "Description": "Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect \"sources\" (origins of input) with \"sinks\" (destinations where the data interacts with external components, a lower layer such as the OS, etc.)", "Effectiveness": "High"}}, "Demonstrative_Examples": {"Demonstrative_Example": {"Intro_Text": "The following code excerpt handles three types of exceptions in an identical fashion.", "Example_Code": [{"@Nature": "Good", "@Language": "Java", "xhtml:div": {"xhtml:div": [{"@style": "margin-left:1em;", "#text": "doExchange();"}, {"@style": "margin-left:1em;", "#text": "logger.error(\"doExchange failed\", e);"}, {"@style": "margin-left:1em;", "xhtml:div": {"xhtml:br": null, "#text": "logger.error(\"doExchange failed\", e);"}}, {"@style": "margin-left:1em;", "xhtml:div": {"xhtml:br": null, "#text": "logger.error(\"doExchange failed\", e);"}}], "xhtml:br": [null, null, null], "#text": "try {}catch (IOException e) {}catch (InvocationTargetException e) {}catch (SQLException e) {}"}}, {"@Nature": "Bad", "@Language": "Java", "xhtml:div": {"xhtml:div": [{"@style": "margin-left:1em;", "#text": "doExchange();"}, {"@style": "margin-left:1em;", "#text": "logger.error(\"doExchange failed\", e);"}], "xhtml:br": null, "#text": "try {}catch (Exception e) {}"}}], "Body_Text": ["At first blush, it may seem preferable to deal with these exceptions in a single catch block, as follows:", "However, if doExchange() is modified to throw a new type of exception that should be handled in some different kind of way, the broad catch block will prevent the compiler from pointing out the situation. Further, the new catch block will now also handle exceptions derived from RuntimeException such as ClassCastException, and NullPointerException, which is not the programmer's intent."]}}, "Taxonomy_Mappings": {"Taxonomy_Mapping": [{"@Taxonomy_Name": "7 Pernicious Kingdoms", "Entry_Name": "Overly-Broad Catch Block"}, {"@Taxonomy_Name": "Software Fault Patterns", "Entry_ID": "SFP5", "Entry_Name": "Ambiguous Exception Type"}, {"@Taxonomy_Name": "OMG ASCSM", "Entry_ID": "ASCSM-CWE-396"}, {"@Taxonomy_Name": "OMG ASCRM", "Entry_ID": "ASCRM-CWE-396"}]}, "References": {"Reference": [{"@External_Reference_ID": "REF-6"}, {"@External_Reference_ID": "REF-44", "@Section": "\"Sin 9: Catching Exceptions.\" Page 157"}, {"@External_Reference_ID": "REF-961", "@Section": "ASCRM-CWE-396"}, {"@External_Reference_ID": "REF-962", "@Section": "ASCSM-CWE-396"}]}, "Mapping_Notes": {"Usage": "Allowed", "Rationale": "This CWE entry is at the Base 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"}}}, "Content_History": {"Submission": {"Submission_Name": "7 Pernicious Kingdoms", "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 Time_of_Introduction"}, {"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 Applicable_Platforms, Relationships, Other_Notes, Taxonomy_Mappings"}, {"Modification_Name": "CWE Content Team", "Modification_Organization": "MITRE", "Modification_Date": "2008-09-24", "Modification_Version": "1.1", "Modification_ReleaseDate": "2008-11-25", "Modification_Comment": "Removed C from Applicable_Platforms"}, {"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 Applicable_Platforms"}, {"Modification_Name": "CWE Content Team", "Modification_Organization": "MITRE", "Modification_Date": "2009-03-10", "Modification_Version": "1.3", "Modification_ReleaseDate": "2009-03-10", "Modification_Comment": "updated Relationships"}, {"Modification_Name": "CWE Content Team", "Modification_Organization": "MITRE", "Modification_Date": "2009-05-27", "Modification_Version": "1.4", "Modification_ReleaseDate": "2009-05-27", "Modification_Comment": "updated Demonstrative_Examples"}, {"Modification_Name": "CWE Content Team", "Modification_Organization": "MITRE", "Modification_Date": "2009-10-29", "Modification_Version": "1.6", "Modification_ReleaseDate": "2009-10-29", "Modification_Comment": "updated Description, Other_Notes"}, {"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 References, Relationships"}, {"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, Taxonomy_Mappings"}, {"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 References, Relationships, Taxonomy_Mappings"}, {"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 References"}, {"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 Applicable_Platforms, Description, Detection_Factors, Relationships, Time_of_Introduction"}, {"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": "2025-04-03", "Modification_Version": "4.17", "Modification_ReleaseDate": "2025-04-03", "Modification_Comment": "updated Common_Consequences, Demonstrative_Examples"}, {"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 Relationships, Weakness_Ordinalities"}], "Contribution": {"@Type": "Content", "Contribution_Name": "Drew Buttner", "Contribution_Organization": "MITRE", "Contribution_Date": "2023-03-06", "Contribution_Comment": "Suggested additional Applicable_Platforms and modification to extended description."}, "Previous_Entry_Name": {"@Date": "2008-04-11", "#text": "Overly-Broad Catch Block"}}}