Improper Cleanup on Thrown Exception

Draft Base
Structure: Simple
Description

This vulnerability occurs when a program fails to properly restore its state or release resources after an exception is thrown, leaving the application in an inconsistent or unexpected condition.

Extended Description

In complex functions or loops, temporary resources like file handles, database connections, or memory allocations often need careful management. When an exception interrupts the normal execution flow, cleanup code that runs during a successful path might be skipped entirely. This leaves resources dangling or data in a partially modified state, which can cause crashes, data corruption, or security issues like information disclosure. Managing this at scale is difficult; an ASPM like Plexicus can help you track and remediate these flaws across your entire stack. While SAST tools can identify risky patterns, Plexicus uses AI to analyze execution paths and suggest specific fixes—such as implementing finally blocks or using try-with-resources constructs—saving hours of manual code review and preventing unstable application behavior.

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
ID: REF-18
Likelihood of Exploit

Medium

Applicable Platforms
Languages:
C : UndeterminedC++ : UndeterminedJava : UndeterminedC# : Undetermined
Modes of Introduction
Implementation
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