Improper Cleanup on Thrown Exception

Draft Base

Structure: Simple

Description

The product does not clean up its state or incorrectly cleans up its state when an exception is thrown, leading to unexpected state or control flow.

Extended Description

Often, when functions or loops become complicated, some level of resource cleanup is needed throughout execution. Exceptions can disturb the flow of the code and prevent the necessary cleanup from happening.

Common Consequences 1

Scope: Other

Impact: Varies by Context

The code could be left in a bad state.

Detection Methods 1

Automated Static AnalysisHigh

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.)

Potential Mitigations 1

Phase: Implementation

If one breaks from a loop or function by throwing an exception, make sure that cleanup happens or that you should exit the program. Use throwing exceptions sparsely.

Demonstrative Examples 1

The following example demonstrates the weakness.

Code Example:

Bad

Java

java

//check some condition* ) { ``` threadLock=true; //do some stuff to truthvalue threadLock=false; } } catch (Exception e){ System.err.println("You did something bad"); if (something) return truthvalue; } return truthvalue; } }

In this case, a thread might be left locked accidentally.

References 1

The CLASP Application Security Process

Secure Software, Inc.

2005

https://cwe.mitre.org/documents/sources/TheCLASPApplicationSecurityProcess.pdf(2024-11-17)

ID: REF-18

Likelihood of Exploit

Medium

Applicable Platforms

Languages:

C : UndeterminedC++ : UndeterminedJava : UndeterminedC# : Undetermined

Modes of Introduction

Implementation

Related Weaknesses

ChildOf:

Incomplete Cleanup (CWE-459)

ChildOf:

Improper Handling of Exceptional Conditions (CWE-755)

Taxonomy Mapping

CLASP
The CERT Oracle Secure Coding Standard for Java (2011)
The CERT Oracle Secure Coding Standard for Java (2011)
SEI CERT Perl Coding Standard