CWE-1071 Base Incomplete

Empty Code Block

An empty code block occurs when a section of source code, such as a conditional statement or function body, contains no executable statements.

Definition

What is CWE-1071?

An empty code block occurs when a section of source code, such as a conditional statement or function body, contains no executable statements.
Empty blocks can appear in various places like if/else conditionals, loops, function definitions, or exception handlers. While sometimes intentionally used as a placeholder, they often signal problems like incomplete features, accidentally deleted logic, or unexpected behavior from macros or code generators. For developers, these empty blocks are a red flag. Even if the language syntax allows them, they frequently violate API contracts or expected program behavior, leading to silent failures or security issues where an action is assumed but never executed. Code reviews should actively identify and justify any empty block to prevent unintentional gaps in application logic.
Real-world impact

Real-world CVEs caused by CWE-1071

No public CVE references are linked to this CWE in MITRE's catalog yet.

How attackers exploit it

Step-by-step attacker path

  1. 1

    In the following Java example, the code catches an ArithmeticException.

  2. 2

    Since the exception block is empty, no action is taken.

  3. 3

    In the code below the exception has been logged and the bad execution has been handled in the desired way allowing the program to continue in an expected way.

  4. 4

    The following code attempts to synchronize on an object, but does not execute anything in the synchronized block. This does not actually accomplish anything and may be a sign that a programmer is wrestling with synchronization but has not yet achieved the result they intend.

  5. 5

    Instead, in a correct usage, the synchronized statement should contain procedures that access or modify data that is exposed to multiple threads. For example, consider a scenario in which several threads are accessing student records at the same time. The method which sets the student ID to a new value will need to make sure that nobody else is accessing this data at the same time and will require synchronization.

Vulnerable code example

Vulnerable Java

In the following Java example, the code catches an ArithmeticException.

Vulnerable Java 
public class Main {
  	public static void main(String[] args) { 
  		int a = 1; 
  		int b = 0; 
  		int c = 0;
  		try { 
  			c = a / b;
  		} catch(ArithmeticException ae) { 
  		}
  	}
  }
Secure code example

Secure Java

In the code below the exception has been logged and the bad execution has been handled in the desired way allowing the program to continue in an expected way.

Secure Java 
public class Main {
  	public static void main(String[] args) { 
  		int a = 1; 
  		int b = 0; 
  		int c = 0;
  		try { 
  			c = a / b;
  		} catch(ArithmeticException ae) { 
  			log.error("Divided by zero detected, setting to -1."); 
  			c = -1;
  		}
  	}
  }
What changed: the unsafe sink is replaced (or the input is validated/escaped) so the same payload no longer triggers the weakness.
Prevention checklist

How to prevent CWE-1071

  • Architecture Use safe-by-default frameworks and APIs that prevent the unsafe pattern from being expressible.
  • Implementation Validate input at trust boundaries; use allowlists, not denylists.
  • Implementation Apply the principle of least privilege to credentials, file paths, and runtime permissions.
  • Testing Cover this weakness in CI: SAST rules + targeted unit tests for the data flow.
  • Operation Monitor logs for the runtime signals listed in the next section.
Detection signals

How to detect CWE-1071

SAST High

Run static analysis (SAST) on the codebase looking for the unsafe pattern in the data flow.

DAST Moderate

Run dynamic application security testing against the live endpoint.

Runtime Moderate

Watch runtime logs for unusual exception traces, malformed input, or authorization bypass attempts.

Code review Moderate

Code review: flag any new code that handles input from this surface without using the validated framework helpers.

Plexicus auto-fix

Plexicus auto-detects CWE-1071 and opens a fix PR in under 60 seconds.

Codex Remedium scans every commit, identifies this exact weakness, and ships a reviewer-ready pull request with the patch. No tickets. No hand-offs.

Get a demo Try Plexicus free
Frequently asked questions

Frequently asked questions

What is CWE-1071?

An empty code block occurs when a section of source code, such as a conditional statement or function body, contains no executable statements.

How serious is CWE-1071?

MITRE has not published a likelihood-of-exploit rating for this weakness. Treat it as medium-impact until your threat model proves otherwise.

What languages or platforms are affected by CWE-1071?

MITRE has not specified affected platforms for this CWE — it can apply across most application stacks.

How can I prevent CWE-1071?

Use safe-by-default frameworks, validate untrusted input at trust boundaries, and apply the principle of least privilege. Cover the data-flow signature in CI with SAST.

How does Plexicus detect and fix CWE-1071?

Plexicus's SAST engine matches the data-flow signature for CWE-1071 on every commit. When a match is found, our Codex Remedium agent opens a fix PR with the corrected code, tests, and a one-line summary for the reviewer.

Where can I learn more about CWE-1071?

MITRE publishes the canonical definition at https://cwe.mitre.org/data/definitions/1071.html. You can also reference OWASP and NIST documentation for adjacent guidance.

Related weaknesses

Weaknesses related to CWE-1071

CWE-1164 Parent

Irrelevant Code

Irrelevant code refers to sections of a program that have no impact on its execution, data, or logic. Removing this code would not change…

CWE-107 Sibling

Struts: Unused Validation Form

This vulnerability occurs when a Struts application contains validation form definitions that are no longer linked to any active form or…

CWE-110 Sibling

Struts: Validator Without Form Field

This vulnerability occurs when a Struts application's validation configuration file references form fields that no longer exist in the…

CWE-561 Sibling

Dead Code

Dead code refers to sections of a program that can never run during normal execution, effectively making them inactive and unreachable.

CWE-563 Sibling

Assignment to Variable without Use

This vulnerability occurs when a value is stored in a variable, but that variable is never read or used in subsequent code, creating a…

CWE-1069 Child

Empty Exception Block

This weakness occurs when a try-catch or try-finally block is present but contains no code to handle the caught exception or perform…

CWE-585 Child

Empty Synchronized Block

An empty synchronized block is a Java code construct where a synchronized block exists but contains no executable statements inside it.

Resources

Further reading

Ready when you are

Don't Let Security
Weigh You Down.

Stop choosing between AI velocity and security debt. Plexicus is the only platform that runs Vibe Coding Security and ASPM in parallel — one workflow, every codebase.

Get started free Book a demo