CWE-1394 Base Incomplete

Use of Default Cryptographic Key

This vulnerability occurs when a system uses a pre-configured, publicly known cryptographic key for security-critical operations instead of generating a unique one.

Definition

What is CWE-1394?

This vulnerability occurs when a system uses a pre-configured, publicly known cryptographic key for security-critical operations instead of generating a unique one.
Developers and manufacturers sometimes embed default cryptographic keys to simplify initial setup, manufacturing, or deployment. While convenient, this practice creates a severe security flaw if these keys are never changed, as they become a universal 'master key' known to attackers. Attackers can exploit this by using the publicly available default key to bypass authentication, decrypt sensitive data, or forge communications across every system that hasn't been properly configured. To prevent this, systems must be designed to require unique, strong keys generated during installation or first use, and administrators must be clearly prompted to change any defaults.
Real-world impact

Real-world CVEs caused by CWE-1394

  • CVE-2018-3825

    cloud cluster management product has a default master encryption key

  • CVE-2016-1561

    backup storage product has a default SSH public key in the authorized_keys file, allowing root access

  • CVE-2010-2306

    Intrusion Detection System (IDS) uses the same static, private SSL keys for multiple devices and installations, allowing decryption of SSL traffic

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-1394

  • Requirements Prohibit use of default, hard-coded, or other values that do not vary for each installation of the product - especially for separate organizations.
  • Architecture and Design Force the administrator to change the credential upon installation.
  • Installation / Operation The product administrator could change the defaults upon installation or during operation.
Detection signals

How to detect CWE-1394

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-1394 and opens a fix PR in under 60 seconds.

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Frequently asked questions

Frequently asked questions

What is CWE-1394?

This vulnerability occurs when a system uses a pre-configured, publicly known cryptographic key for security-critical operations instead of generating a unique one.

How serious is CWE-1394?

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-1394?

MITRE lists the following affected platforms: Not OS-Specific, Not Architecture-Specific, Not Technology-Specific.

How can I prevent CWE-1394?

Prohibit use of default, hard-coded, or other values that do not vary for each installation of the product - especially for separate organizations. Force the administrator to change the credential upon installation.

How does Plexicus detect and fix CWE-1394?

Plexicus's SAST engine matches the data-flow signature for CWE-1394 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-1394?

MITRE publishes the canonical definition at https://cwe.mitre.org/data/definitions/1394.html. You can also reference OWASP and NIST documentation for adjacent guidance.

Related weaknesses

Weaknesses related to CWE-1394

CWE-1392 Parent

Use of Default Credentials

This vulnerability occurs when a system, device, or application relies on pre-configured, publicly known credentials like passwords or…

CWE-1393 Sibling

Use of Default Password

This vulnerability occurs when a system or device uses a pre-configured, publicly known password for authentication, often for…

Resources

Further reading

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