Run static analysis (SAST) on the codebase looking for the unsafe pattern in the data flow.
CWE-541 Variant Incomplete
Inclusion of Sensitive Information in an Include File
This vulnerability occurs when sensitive data like passwords or system details is placed inside a publicly accessible include file. Attackers can directly request these files to steal credentials…
Definition
What is CWE-541?
This vulnerability occurs when sensitive data like passwords or system details is placed inside a publicly accessible include file. Attackers can directly request these files to steal credentials and compromise the application.
Include files (like .inc, .config, or library files) are often used to store common code or configuration settings. When these files contain hard-coded secrets such as database passwords, API keys, or administrative credentials, and are left in a web-accessible directory, they become a prime target. Attackers can simply browse to the file's URL to download its full source code, bypassing the main application's security controls entirely.
To prevent this, never store sensitive information within web-accessible include files. Instead, move configuration containing secrets outside the web root or into environment variables and protected configuration files. Additionally, configure your web server to deny requests to files with common include extensions, and ensure your deployment process cleans directories of development or backup files that might inadvertently expose data.
Real-world impact
Real-world CVEs caused by CWE-541
No public CVE references are linked to this CWE in MITRE's catalog yet.
How attackers exploit it
Step-by-step attacker path
- 1
The following code uses an include file to store database credentials:
- 2
database.inc
- 3
login.php
- 4
If the server does not have an explicit handler set for .inc files it may send the contents of database.inc to an attacker without pre-processing, if the attacker requests the file directly. This will expose the database name and password.
Vulnerable code example
Vulnerable PHP
database.inc
<?php
$dbName = 'usersDB';
$dbPassword = 'skjdh#67nkjd3$3$';
?> Secure code example
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-541
- Architecture and Design Do not store sensitive information in include files.
- Architecture and Design / System Configuration Protect include files from being exposed.
Detection signals
How to detect CWE-541
Run dynamic application security testing against the live endpoint.
Watch runtime logs for unusual exception traces, malformed input, or authorization bypass attempts.
Code review: flag any new code that handles input from this surface without using the validated framework helpers.
CWE-541
Don't catalog this weakness. Prove it's reachable.
Plexicus turns CWE catalogs into evidence: every CWE-pattern is matched against your real code graph, reach is proven on a sandbox clone, and verified findings ship as reviewed PRs.
Frequently asked questions What is CWE-541?
How serious is CWE-541?
What languages or platforms are affected by CWE-541?
How can I prevent CWE-541?
How does Plexicus detect and fix CWE-541?
Where can I learn more about CWE-541?
Frequently asked questions
What is CWE-541?
This vulnerability occurs when sensitive data like passwords or system details is placed inside a publicly accessible include file. Attackers can directly request these files to steal credentials and compromise the application.
How serious is CWE-541?
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-541?
MITRE has not specified affected platforms for this CWE — it can apply across most application stacks.
How can I prevent CWE-541?
Do not store sensitive information in include files. Protect include files from being exposed.
How does Plexicus detect and fix CWE-541?
Plexicus's SAST engine matches the data-flow signature for CWE-541 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-541?
MITRE publishes the canonical definition at https://cwe.mitre.org/data/definitions/541.html. You can also reference OWASP and NIST documentation for adjacent guidance.
Related weaknesses
Weaknesses related to CWE-541
CWE-540 Parent
Inclusion of Sensitive Information in Source Code
This vulnerability occurs when sensitive information like passwords, API keys, or internal logic is exposed within source code that…
CWE-531 Sibling
Inclusion of Sensitive Information in Test Code
This vulnerability occurs when sensitive data, such as credentials, API keys, or internal logic, is embedded within test code or debugging…
CWE-615 Sibling
Inclusion of Sensitive Information in Source Code Comments
This vulnerability occurs when developers leave sensitive details within source code comments. These can include internal file paths,…
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