CWE-257 Base Incomplet High likelihood

Storing Passwords in a Recoverable Format

This vulnerability occurs when an application stores user passwords in a format that can be easily reversed or decrypted back to their original plaintext form. This practice, often called storing…

Définition

What is CWE-257?

This vulnerability occurs when an application stores user passwords in a format that can be easily reversed or decrypted back to their original plaintext form. This practice, often called storing 'recoverable' passwords, defeats the core purpose of password protection. It allows anyone with access to the stored data—including attackers who breach the system or even malicious insiders—to obtain and reuse the actual passwords on other accounts, offering no real security advantage over storing them in plain text.
When passwords are stored in a recoverable format, such as using weak or reversible encryption instead of a proper one-way hash, the system inherently retains the ability to convert them back. This creates a single point of failure: if the storage is compromised or accessed by an unauthorized party, every password becomes immediately usable for account takeover and credential stuffing attacks across other services. The risk is identical to storing plaintext passwords, as the decryption key or method is typically accessible within the application's environment. From a security perspective, there is no legitimate operational need for developers or system administrators to retrieve a user's original password. Standard authentication should compare a one-way hash of the entered password against a stored hash. Any design that requires password recovery is flawed; a secure system should only offer a password reset function. Relying on reversible storage undermines user trust and system integrity, as it enables abuse by both external attackers and privileged insiders who can decrypt credentials at will.
Impact réel

Real-world CVEs caused by CWE-257

  • A messaging platform serializes all elements of User/Group objects, making private information available to adversaries

Comment les attaquants l'exploitent

Parcours de l'attaquant étape par étape

  1. 1

    Both of these examples verify a password by comparing it to a stored compressed version.

  2. 2

    Because a compression algorithm is used instead of a one way hashing algorithm, an attacker can recover compressed passwords stored in the database.

  3. 3

    The following examples show a portion of properties and configuration files for Java and ASP.NET applications. The files include username and password information but they are stored in cleartext.

  4. 4

    This Java example shows a properties file with a cleartext username / password pair.

  5. 5

    The following example shows a portion of a configuration file for an ASP.Net application. This configuration file includes username and password information for a connection to a database but the pair is stored in cleartext.

Exemple de code vulnérable

Vulnerable C

Both of these examples verify a password by comparing it to a stored compressed version.

Vulnérable C
int VerifyAdmin(char *password) {
  	if (strcmp(compress(password), compressed_password)) {
  		printf("Incorrect Password!\n");
  		return(0);
  	}
  	printf("Entering Diagnostic Mode...\n");
  	return(1);
  }
Exemple de code sécurisé

Secure pseudo

Sécurisé 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.
Liste de contrôle de prévention

How to prevent CWE-257

  • Architecture and Design Use strong, non-reversible encryption to protect stored passwords.
Signaux de détection

How to detect CWE-257

Automated Static Analysis High

Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.)

Correction automatique Plexicus

Plexicus détecte automatiquement CWE-257 et ouvre une PR de correction en moins de 60 secondes.

Codex Remedium analyse chaque commit, identifie cette faiblesse précise et livre une pull request prête à être relue avec le correctif. Pas de tickets. Pas de transferts.

Questions fréquentes

Frequently asked questions

Qu'est-ce que CWE-257 ?

This vulnerability occurs when an application stores user passwords in a format that can be easily reversed or decrypted back to their original plaintext form. This practice, often called storing 'recoverable' passwords, defeats the core purpose of password protection.

Quelle est la gravité de CWE-257 ?

MITRE évalue la probabilité d'exploitation comme Élevée — cette faiblesse est activement exploitée et doit être priorisée pour la remédiation.

Quels langages ou plateformes sont affectés par CWE-257 ?

MITRE n'a pas spécifié les plateformes affectées pour ce CWE — il peut s'appliquer à la plupart des stacks applicatives.

Comment puis-je prévenir CWE-257 ?

Use strong, non-reversible encryption to protect stored passwords.

Comment Plexicus détecte et corrige CWE-257 ?

Le moteur SAST de Plexicus reconnaît la signature de flux de données de CWE-257 à chaque commit. Lorsqu'une correspondance est trouvée, notre agent Codex Remedium ouvre une PR de correction avec le code corrigé, les tests et un résumé d'une ligne pour le relecteur.

Où puis-je en savoir plus sur CWE-257 ?

MITRE publie la définition canonique à https://cwe.mitre.org/data/definitions/257.html. Vous pouvez également consulter la documentation OWASP et NIST pour des conseils adjacents.

Prêt quand vous l'êtes

Arrêtez de payer par développeur.
Commencez à fermer la boucle.

Plexicus est l'ASPM natif IA qui scanne, filtre, corrige, penteste et explique — de façon autonome. Développeurs illimités, dépôts illimités, actions IA à usage équitable. Vrai niveau gratuit, €269/mo annuel quand vous êtes prêt.