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Detection of Error Condition Without Action

Draft Base
Structure: Simple
Description

This weakness occurs when software successfully identifies an error condition but then fails to take any meaningful action to address it. The error is detected but ignored, leaving the system in an inconsistent or vulnerable state.

Extended Description

Imagine your code checks for a failed login attempt, a missing file, or a network timeout, but then simply logs the event and continues normal execution as if nothing went wrong. This creates a silent failure where the root problem isn't corrected, and the application might proceed using bad data, null pointers, or unstable connections. The core issue is that detection logic is present, but the crucial response—like rolling back a transaction, showing a user-friendly alert, or falling back to a secure default—is completely missing. For developers, this often stems from placeholder error handling, such as empty `catch` blocks or generic logging statements that don't trigger remediation. To fix it, every error check must have a defined outcome: terminate the operation safely, retry with limitations, notify the user appropriately, or revert to a known good state. Treating error detection as a separate step from the response action leaves critical security and stability gaps that attackers or unexpected conditions can easily exploit.
Common Consequences 1
Scope: IntegrityOther

Impact: Varies by ContextUnexpected StateAlter Execution Logic

An attacker could utilize an ignored error condition to place the system in an unexpected state that could lead to the execution of unintended logic and could cause other unintended behavior.
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 3
Phase: Implementation
Properly handle each exception. This is the recommended solution. Ensure that all exceptions are handled in such a way that you can be sure of the state of your system at any given moment.
Phase: Implementation
If a function returns an error, it is important to either fix the problem and try again, alert the user that an error has happened and let the program continue, or alert the user and close and cleanup the program.
Phase: Testing
Subject the product to extensive testing to discover some of the possible instances of where/how errors or return values are not handled. Consider testing techniques such as ad hoc, equivalence partitioning, robustness and fault tolerance, mutation, and fuzzing.
Demonstrative Examples 3

ID : DX-201

The following example attempts to allocate memory for a character. After the call to malloc, an if statement is used to check whether the malloc function failed.

Code Example:

Bad
C
c
The conditional successfully detects a NULL return value from malloc indicating a failure, however it does not do anything to handle the problem. Unhandled errors may have unexpected results and may cause the program to crash or terminate.
Instead, the if block should contain statements that either attempt to fix the problem or notify the user that an error has occurred and continue processing or perform some cleanup and gracefully terminate the program. The following example notifies the user that the malloc function did not allocate the required memory resources and returns an error code.

Code Example:

Good
C
c
In the following C++ example the method readFile() will read the file whose name is provided in the input parameter and will return the contents of the file in char string. The method calls open() and read() may result in errors if the file does not exist or does not contain any data to read. These errors will be thrown when the is_open() method and good() method indicate errors opening or reading the file. However, these errors are not handled within the catch statement. Catch statements that do not perform any processing will have unexpected results. In this case an empty char string will be returned, and the file will not be properly closed.

Code Example:

Bad
C++
c++
The catch statement should contain statements that either attempt to fix the problem or notify the user that an error has occurred and continue processing or perform some cleanup and gracefully terminate the program. The following C++ example contains two catch statements. The first of these will catch a specific error thrown within the try block, and the second catch statement will catch all other errors from within the catch block. Both catch statements will notify the user that an error has occurred, close the file, and rethrow to the block that called the readFile() method for further handling or possible termination of the program.

Code Example:

Good
C++
c++
In the following Java example the method readFile will read the file whose name is provided in the input parameter and will return the contents of the file in a String object. The constructor of the FileReader object and the read method call may throw exceptions and therefore must be within a try/catch block. While the catch statement in this example will catch thrown exceptions in order for the method to compile, no processing is performed to handle the thrown exceptions. Catch statements that do not perform any processing will have unexpected results. In this case, this will result in the return of a null String.

Code Example:

Bad
Java
java
The catch statement should contain statements that either attempt to fix the problem, notify the user that an exception has been raised and continue processing, or perform some cleanup and gracefully terminate the program. The following Java example contains three catch statements. The first of these will catch the FileNotFoundException that may be thrown by the FileReader constructor called within the try/catch block. The second catch statement will catch the IOException that may be thrown by the read method called within the try/catch block. The third catch statement will catch all other exceptions thrown within the try block. For all catch statements the user is notified that the exception has been thrown and the exception is rethrown to the block that called the readFile() method for further processing or possible termination of the program. Note that with Java it is usually good practice to use the getMessage() method of the exception class to provide more information to the user about the exception raised.

Code Example:

Good
Java
java
Observed Examples 1
CVE-2022-21820A GPU data center manager detects an error due to a malformed request but does not act on it, leading to memory corruption.
References 2
The CLASP Application Security Process
Secure Software, Inc.
2005
https://cwe.mitre.org/documents/sources/TheCLASPApplicationSecurityProcess.pdf(2024-11-17)
ID: REF-18
24 Deadly Sins of Software Security
Michael Howard, David LeBlanc, and John Viega
McGraw-Hill
2010
ID: REF-44
Likelihood of Exploit

Medium

Applicable Platforms
Languages:
Not Language-Specific : Undetermined
Modes of Introduction
Implementation
Related Weaknesses
ChildOf: Improper Handling of Exceptional Conditions (CWE-755)
CanPrecede: Missing Release of Memory after Effective Lifetime (CWE-401)
Taxonomy Mapping
  • CLASP
  • The CERT Oracle Secure Coding Standard for Java (2011)
  • Software Fault Patterns