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.)
CWE-760 Variante Incompleto
Use of a One-Way Hash with a Predictable Salt
This vulnerability occurs when an application uses a one-way hash (like for password storage) but combines it with a predictable or easily guessed salt. This undermines the security benefit of…
Definición
What is CWE-760?
This vulnerability occurs when an application uses a one-way hash (like for password storage) but combines it with a predictable or easily guessed salt. This undermines the security benefit of salting, making pre-computed attack methods like rainbow tables highly effective.
Using a predictable salt, such as a username or a static string, allows attackers to bypass the primary defense salting provides. Attackers can pre-generate massive lookup tables (rainbow tables) for that specific salt, enabling them to quickly reverse hashes and recover credentials. This effectively nullifies the security advantage that a random, unique salt is meant to deliver.
It's important to understand that even a strong, random salt is not a complete solution against determined attackers with significant resources, as hashing algorithms are designed for speed. Modern password cracking using cloud or specialized hardware can still be effective. For robust protection, consider adaptive, computationally expensive hash functions (like Argon2, scrypt, or bcrypt) designed specifically for passwords. Identifying and fixing these predictable salt patterns across a large codebase can be challenging; an ASPM platform like Plexicus can automatically detect such flaws via SAST and use AI to provide specific remediation guidance, streamlining the fix process.
Impacto en el mundo real
Real-world CVEs caused by CWE-760
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Blogging software uses a hard-coded salt when calculating a password hash.
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Database server uses the username for a salt when encrypting passwords, simplifying brute force attacks.
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Server uses a constant salt when encrypting passwords, simplifying brute force attacks.
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chain: product generates predictable MD5 hashes using a constant value combined with username, allowing authentication bypass.
Cómo lo explotan los atacantes
Ruta del atacante paso a paso
- 1
Identifica una ruta de código que maneje entrada no confiable sin validación.
- 2
Crea un payload que ejercite el comportamiento inseguro — inyección, traversal, overflow o abuso de lógica.
- 3
Envía el payload a través de una solicitud normal y observa la reacción de la aplicación.
- 4
Itera hasta que la respuesta filtre datos, ejecute código del atacante o escale privilegios.
Ejemplo de código vulnerable
Vulnerable pseudo
MITRE no ha publicado un ejemplo de código para esta CWE. El patrón siguiente es ilustrativo — consulta Recursos para referencias canónicas.
// Example pattern — see MITRE for the canonical references.
function handleRequest(input) {
// Untrusted input flows directly into the sensitive sink.
return executeUnsafe(input);
} Ejemplo de código seguro
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.
Lista de prevención
How to prevent CWE-760
- Architecture and Design Use an adaptive hash function that can be configured to change the amount of computational effort needed to compute the hash, such as the number of iterations ("stretching") or the amount of memory required. Some hash functions perform salting automatically. These functions can significantly increase the overhead for a brute force attack compared to intentionally-fast functions such as MD5. For example, rainbow table attacks can become infeasible due to the high computing overhead. Finally, since computing power gets faster and cheaper over time, the technique can be reconfigured to increase the workload without forcing an entire replacement of the algorithm in use. Some hash functions that have one or more of these desired properties include bcrypt [REF-291], scrypt [REF-292], and PBKDF2 [REF-293]. While there is active debate about which of these is the most effective, they are all stronger than using salts with hash functions with very little computing overhead. Note that using these functions can have an impact on performance, so they require special consideration to avoid denial-of-service attacks. However, their configurability provides finer control over how much CPU and memory is used, so it could be adjusted to suit the environment's needs.
- Implementation If a technique that requires extra computational effort can not be implemented, then for each password that is processed, generate a new random salt using a strong random number generator with unpredictable seeds. Add the salt to the plaintext password before hashing it. When storing the hash, also store the salt. Do not use the same salt for every password.
Señales de detección
How to detect CWE-760
CWE-760
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.
Preguntas frecuentes ¿Qué es CWE-760?
¿Qué gravedad tiene CWE-760?
¿Qué lenguajes o plataformas se ven afectados por CWE-760?
¿Cómo puedo prevenir CWE-760?
¿Cómo detecta y corrige Plexicus CWE-760?
¿Dónde puedo aprender más sobre CWE-760?
Frequently asked questions
¿Qué es CWE-760?
This vulnerability occurs when an application uses a one-way hash (like for password storage) but combines it with a predictable or easily guessed salt. This undermines the security benefit of salting, making pre-computed attack methods like rainbow tables highly effective.
¿Qué gravedad tiene CWE-760?
MITRE no ha publicado una calificación de probabilidad de explotación para esta debilidad. Trátala como de impacto medio hasta que tu modelo de amenazas demuestre lo contrario.
¿Qué lenguajes o plataformas se ven afectados por CWE-760?
MITRE no ha especificado plataformas afectadas para esta CWE — puede aplicar a la mayoría de los stacks de aplicaciones.
¿Cómo puedo prevenir CWE-760?
Use an adaptive hash function that can be configured to change the amount of computational effort needed to compute the hash, such as the number of iterations ("stretching") or the amount of memory required. Some hash functions perform salting automatically. These functions can significantly increase the overhead for a brute force attack compared to intentionally-fast functions such as MD5. For example, rainbow table attacks can become infeasible due to the high computing overhead. Finally,…
¿Cómo detecta y corrige Plexicus CWE-760?
El motor SAST de Plexicus detecta la firma de flujo de datos para CWE-760 en cada commit. Cuando hay coincidencia, nuestro agente Codex Remedium abre un PR de corrección con el código corregido, las pruebas y un resumen de una línea para el revisor.
¿Dónde puedo aprender más sobre CWE-760?
MITRE publica la definición canónica en https://cwe.mitre.org/data/definitions/760.html. También puedes consultar la documentación de OWASP y NIST para guías relacionadas.
Debilidades relacionadas
Weaknesses related to CWE-760
CWE-916 Padre
Use of Password Hash With Insufficient Computational Effort
This vulnerability occurs when a system protects passwords by hashing them, but uses a hashing algorithm that is too fast or…
CWE-759 Hermano
Use of a One-Way Hash without a Salt
This vulnerability occurs when a system uses a one-way hash function (like MD5 or SHA-256) to protect sensitive data like passwords, but…
Recursos
Further reading
- MITRE — CWE-760 oficial https://cwe.mitre.org/data/definitions/760.html
- bcrypt https://bcrypt.sourceforge.net/
- Tarsnap - The scrypt key derivation function and encryption utility http://www.tarsnap.com/scrypt.html
- RFC2898 - PKCS #5: Password-Based Cryptography Specification Version 2.0 https://www.rfc-editor.org/rfc/rfc2898
- How To Safely Store A Password https://codahale.com/how-to-safely-store-a-password/
- How Companies Can Beef Up Password Security (interview with Thomas H. Ptacek) https://krebsonsecurity.com/2012/06/how-companies-can-beef-up-password-security/
- Password security: past, present, future https://www.openwall.com/presentations/PHDays2012-Password-Security/
¿Listo para validar lo que importa?
Listo para validar lo que importa.
Plexicus es Proof-Driven AppSec: hallazgos validados, comprensión contextual y remediación revisada — anclada en evidencia, acotada contigo.