CWE-1327 Base Incomplete

Binding to an Unrestricted IP Address

This vulnerability occurs when software or a service is configured to bind to the IP address 0.0.0.0 (or :: in IPv6), which acts as a wildcard, accepting connections from any network interface on…

Definition

What is CWE-1327?

This vulnerability occurs when software or a service is configured to bind to the IP address 0.0.0.0 (or :: in IPv6), which acts as a wildcard, accepting connections from any network interface on the host system.
Binding to 0.0.0.0 tells the server to listen for connections on all available network interfaces—including public, private, and localhost addresses. While this is sometimes necessary for development or specific services, it often unintentionally exposes the service to networks it shouldn't be accessible from, like the public internet, when only a specific internal or management network was intended. This creates a significant security gap by bypassing network segmentation and firewall controls. An attacker who can reach any of the host's interfaces can potentially connect to the service. Developers should explicitly bind to specific, intended IP addresses (like 127.0.0.1 for local-only or a specific internal IP) to enforce the principle of least privilege and reduce the system's attack surface.
Real-world impact

Real-world CVEs caused by CWE-1327

  • CVE-2022-21947

    Desktop manager for Kubernetes and container management binds a service to 0.0.0.0, allowing users on the network to make requests to a dashboard API.

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 Other

The following code snippet uses 0.0.0.0 in a Puppet script.

Vulnerable Other 
signingserver::instance {

```
   "nightly-key-signing-server": 
  	 listenaddr => "0.0.0.0",
  	 port => "9100",
  	 code_tag => "SIGNING_SERVER",
   }
Secure code example

Secure Other

The Puppet code snippet is used to provision a signing server that will use 0.0.0.0 to accept traffic. However, as 0.0.0.0 is unrestricted, malicious users may use this IP address to launch frequent requests and cause denial of service attacks.

Secure Other 
signingserver::instance {

```
   "nightly-key-signing-server": 
  	 listenaddr => "127.0.0.1",
  	 port => "9100",
  	 code_tag => "SIGNING_SERVER",
   }
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-1327

  • System Configuration Assign IP addresses that are not 0.0.0.0.
  • System Configuration Unwanted connections to the configured server may be denied through a firewall or other packet filtering measures.
Detection signals

How to detect CWE-1327

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-1327 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-1327?

This vulnerability occurs when software or a service is configured to bind to the IP address 0.0.0.0 (or :: in IPv6), which acts as a wildcard, accepting connections from any network interface on the host system.

How serious is CWE-1327?

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-1327?

MITRE lists the following affected platforms: Other, Not OS-Specific, Not Architecture-Specific, Web Server, Client Server, Cloud Computing.

How can I prevent CWE-1327?

Assign IP addresses that are not 0.0.0.0. Unwanted connections to the configured server may be denied through a firewall or other packet filtering measures.

How does Plexicus detect and fix CWE-1327?

Plexicus's SAST engine matches the data-flow signature for CWE-1327 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-1327?

MITRE publishes the canonical definition at https://cwe.mitre.org/data/definitions/1327.html. You can also reference OWASP and NIST documentation for adjacent guidance.

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