CWE-1253: Incorrect Selection of Fuse Values

Definition

What is CWE-1253?

This vulnerability occurs when a hardware security fuse is incorrectly programmed to represent a 'secure' state as logic 0 (unblown). An attacker can permanently force the system into an insecure mode simply by blowing the fuse, which flips its value to logic 1.

Hardware fuses are commonly used for one-time programmable (OTP) memory to store secrets or security settings. By design, an unblown fuse reads as a logic 0, while blowing it changes the reading to a logic 1. The security flaw arises when the system's firmware or logic gates are configured with negative logic, interpreting a blown fuse (logic 1) as a command to disable security protections. Since fuses are irreversible, an attacker's single action of blowing the targeted fuse can permanently lock the device into a compromised state. This highlights a critical design error: the secure condition must be represented by the blown (logic 1) state, not the unblown state, to prevent an attacker from easily overriding security by manipulating the fuse.

Real-world impact

Real-world CVEs caused by CWE-1253

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

How attackers exploit it

Step-by-step attacker path

1
Identify a code path that handles untrusted input without validation.
2
Craft a payload that exercises the unsafe behavior — injection, traversal, overflow, or logic abuse.
3
Deliver the payload through a normal request and observe the application's reaction.
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

// 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-1253

Architecture and Design Logic should be designed in a way that blown fuses do not put the product into an insecure state that can be leveraged by an attacker.

Detection signals

How to detect CWE-1253

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.

CWE-1253

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.

Request AI Swarm Pentest

Frequently asked questions

What is CWE-1253?

This vulnerability occurs when a hardware security fuse is incorrectly programmed to represent a 'secure' state as logic 0 (unblown). An attacker can permanently force the system into an insecure mode simply by blowing the fuse, which flips its value to logic 1.

How serious is CWE-1253?

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-1253?

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

How can I prevent CWE-1253?

Logic should be designed in a way that blown fuses do not put the product into an insecure state that can be leveraged by an attacker.

How does Plexicus detect and fix CWE-1253?

Plexicus's SAST engine matches the data-flow signature for CWE-1253 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-1253?

MITRE publishes the canonical definition at https://cwe.mitre.org/data/definitions/1253.html. You can also reference OWASP and NIST documentation for adjacent guidance.

Related weaknesses

Weaknesses related to CWE-1253

CWE-693 Parent

Ready to validate what matters?

Plexicus is Proof-Driven AppSec: validated findings, contextual understanding, and reviewed remediation — anchored in evidence, scoped with you.

Request AI Swarm Pentest

Incorrect Selection of Fuse Values

What is CWE-1253?

Real-world CVEs caused by CWE-1253

Step-by-step attacker path

Vulnerable pseudo

Secure pseudo

How to prevent CWE-1253

How to detect CWE-1253

Don't catalog this weakness. Prove it's reachable.

Frequently asked questions

Weaknesses related to CWE-1253

Protection Mechanism Failure

Inadequate Detection or Handling of Adversarial Input Perturbations in Automated Recognition Mechanism

Semiconductor Defects in Hardware Logic with Security-Sensitive Implications

Product Released in Non-Release Configuration

Missing Protection Against Hardware Reverse Engineering Using Integrated Circuit (IC) Imaging Techniques

Public Key Re-Use for Signing both Debug and Production Code

Missing Support for Security Features in On-chip Fabrics or Buses

Improper Protection against Electromagnetic Fault Injection (EM-FI)

Missing Immutable Root of Trust in Hardware

Further reading

Ready to validate what matters?

Check whether AI Swarm Pentest fits your environment.

Request received. Book the next step.

Sample evidence handover

Server-Side Request Forgery in `webhooks/receiver`