CWE-1107 Base Incomplete

Insufficient Isolation of Symbolic Constant Definitions

This weakness occurs when a codebase uses symbolic constants (like named values for numbers or strings) but scatters their definitions across many files instead of centralizing them in one isolated…

Definition

What is CWE-1107?

This weakness occurs when a codebase uses symbolic constants (like named values for numbers or strings) but scatters their definitions across many files instead of centralizing them in one isolated location, such as a dedicated configuration file or module.
Scattering symbolic constants throughout your code creates a significant maintenance burden. When a value needs to be updated—for example, a timeout duration, a file path, or a magic number—developers must hunt through numerous source files to find every instance. This process is error-prone, time-consuming, and increases the risk of missing a definition, leading to inconsistent behavior and potential bugs. From a security perspective, this poor isolation indirectly weakens your application's defenses. It slows down vulnerability patching because identifying and updating all relevant code locations takes longer. It also makes it easier to accidentally introduce new vulnerabilities during maintenance, as developers might overlook a critical constant or update it incorrectly. Centralizing these definitions is a foundational practice for secure, maintainable code.
Real-world impact

Real-world CVEs caused by CWE-1107

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

    Identify a code path that handles untrusted input without validation.

  2. 2

    Craft a payload that exercises the unsafe behavior — injection, traversal, overflow, or logic abuse.

  3. 3

    Deliver the payload through a normal request and observe the application's reaction.

  4. 4

    Iterate until the response leaks data, executes attacker code, or escalates privileges.

Vulnerable code example

Vulnerable pseudo

MITRE has not published a code example for this CWE. The pattern below is illustrative — see Resources for canonical references.

Vulnerable pseudo 
// Example pattern — see MITRE for the canonical references.
function handleRequest(input) {
  // Untrusted input flows directly into the sensitive sink.
  return executeUnsafe(input);
}
Secure code example

Secure pseudo

Secure pseudo 
// Validate, sanitize, or use a safe API before reaching the sink.
function handleRequest(input) {
  const safe = validateAndEscape(input);
  return executeWithGuards(safe);
}
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-1107

  • 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-1107

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-1107 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.

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Frequently asked questions

Frequently asked questions

What is CWE-1107?

This weakness occurs when a codebase uses symbolic constants (like named values for numbers or strings) but scatters their definitions across many files instead of centralizing them in one isolated location, such as a dedicated configuration file or module.

How serious is CWE-1107?

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-1107?

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

How can I prevent CWE-1107?

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-1107?

Plexicus's SAST engine matches the data-flow signature for CWE-1107 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-1107?

MITRE publishes the canonical definition at https://cwe.mitre.org/data/definitions/1107.html. You can also reference OWASP and NIST documentation for adjacent guidance.

Related weaknesses

Weaknesses related to CWE-1107

CWE-1078 Parent

Inappropriate Source Code Style or Formatting

This weakness occurs when source code violates established style guidelines for formatting, indentation, whitespace, or commenting, making…

CWE-1085 Sibling

Invokable Control Element with Excessive Volume of Commented-out Code

This weakness occurs when a callable function, method, or procedure contains a large amount of inactive, commented-out code within its…

CWE-1099 Sibling

Inconsistent Naming Conventions for Identifiers

This weakness occurs when a codebase uses mixed naming styles for elements like variables, functions, data types, or files, creating an…

CWE-1106 Sibling

Insufficient Use of Symbolic Constants

This weakness occurs when developers embed raw numbers or text strings directly in code instead of using named symbolic constants, making…

CWE-1109 Sibling

Use of Same Variable for Multiple Purposes

This weakness occurs when a single variable is reused to handle multiple, unrelated tasks or to store different pieces of data throughout…

CWE-1113 Sibling

Inappropriate Comment Style

This weakness occurs when source code comments are written in a style or format that doesn't match the project's established standards or…

CWE-1114 Sibling

Inappropriate Whitespace Style

This weakness occurs when source code uses inconsistent or non-standard whitespace formatting, such as irregular indentation, spacing, or…

CWE-1115 Sibling

Source Code Element without Standard Prologue

This weakness occurs when source code files or modules lack a consistent, standardized header or prologue that the development team has…

CWE-1116 Sibling

Inaccurate Comments

This weakness occurs when code comments do not correctly describe or explain the actual behavior of the associated code. Misleading…

Resources

Further reading

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