Reino: Security Features

La seguridad de un software no es un software de seguridad. Nos preocupamos de cuestiones como la autenticación, el control de acceso, la confidencialidad, la criptografía y la gestión de privilegios.

Weak Cryptographic Hash: Null PBE Salt

Abstract

Una sal null (nil) puede poner en riesgo la seguridad del sistema de una forma que no es fácil de resolver.

Explanation

Nunca es una buena idea utilizar sal null (nil). El uso de sal null no solo facilita enormemente que puedan adivinarse los valores de hash, sino que además dificulta enormemente la solución del problema. Una vez que el código está en producción, no es fácil modificar la sal. Si los usuarios malintencionados descubren que los valores con hash tienen sal null, pueden calcular "tablas arco iris" para la aplicación y determinar más fácilmente los valores con hash.

Ejemplo 1: El código siguiente utiliza sal null (nil):


...
CCKeyDerivationPBKDF(kCCPBKDF2,
                     password,
                     passwordLen,
                     nil,
                     0,
                     kCCPRFHmacAlgSHA256,
                     100000,
                     derivedKey,
                     derivedKeyLen);
...

Este código se ejecutará correctamente, pero todo aquel que tenga acceso a él también tendrá acceso a sal null. Una vez que se haya distribuido el programa, no hay otro modo de cambiar la sal null. Un empleado con acceso a esta información podría utilizarla para irrumpir en el sistema.

References

[1] Standards Mapping - Common Weakness Enumeration CWE ID 759

[2] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-001188, CCI-002450

[3] Standards Mapping - FIPS200 MP

[4] Standards Mapping - General Data Protection Regulation (GDPR) Insufficient Data Protection

[5] Standards Mapping - NIST Special Publication 800-53 Revision 4 AU-10 Non-Repudiation (P2), SC-13 Cryptographic Protection (P1), SC-23 Session Authenticity (P1)

[6] Standards Mapping - NIST Special Publication 800-53 Revision 5 AU-10 Non-Repudiation, SC-13 Cryptographic Protection, SC-23 Session Authenticity

[7] Standards Mapping - OWASP Application Security Verification Standard 4.0 2.4.1 Credential Storage Requirements (L2 L3), 2.4.2 Credential Storage Requirements (L2 L3), 2.4.5 Credential Storage Requirements (L2 L3), 2.6.3 Look-up Secret Verifier Requirements (L2 L3), 2.9.3 Cryptographic Software and Devices Verifier Requirements (L2 L3), 6.2.1 Algorithms (L1 L2 L3), 6.2.2 Algorithms (L2 L3), 8.3.7 Sensitive Private Data (L2 L3), 9.1.2 Communications Security Requirements (L1 L2 L3), 9.1.3 Communications Security Requirements (L1 L2 L3)

[8] Standards Mapping - OWASP Mobile 2014 M6 Broken Cryptography

[9] Standards Mapping - OWASP Mobile 2024 M10 Insufficient Cryptography

[10] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-CRYPTO-1

[11] Standards Mapping - OWASP Top 10 2004 A8 Insecure Storage

[12] Standards Mapping - OWASP Top 10 2007 A8 Insecure Cryptographic Storage

[13] Standards Mapping - OWASP Top 10 2010 A7 Insecure Cryptographic Storage

[14] Standards Mapping - OWASP Top 10 2013 A6 Sensitive Data Exposure

[15] Standards Mapping - OWASP Top 10 2017 A3 Sensitive Data Exposure

[16] Standards Mapping - OWASP Top 10 2021 A02 Cryptographic Failures

[17] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.8

[18] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 Requirement 6.3.1.3, Requirement 6.5.8

[19] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 Requirement 6.5.3

[20] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.3

[21] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.3

[22] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.3

[23] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.3

[24] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4

[25] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0.1 Requirement 3.3.2, Requirement 3.3.3, Requirement 3.5.1, Requirement 6.2.4

[26] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 7.1 - Use of Cryptography, Control Objective 7.4 - Use of Cryptography

[27] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 7.1 - Use of Cryptography, Control Objective 7.4 - Use of Cryptography, Control Objective B.2.3 - Terminal Software Design

[28] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 7.1 - Use of Cryptography, Control Objective 7.4 - Use of Cryptography, Control Objective B.2.3 - Terminal Software Design

[29] Standards Mapping - SANS Top 25 2011 Porous Defenses - CWE ID 759

[30] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP3150.1 CAT II

[31] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP3150.1 CAT II

[32] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP3150.1 CAT II

[33] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP3150.1 CAT II

[34] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP3150.1 CAT II

[35] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP3150.1 CAT II

[36] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP3150.1 CAT II

[37] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002010 CAT II, APSC-DV-002020 CAT II, APSC-DV-002030 CAT II

[38] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002010 CAT II, APSC-DV-002020 CAT II, APSC-DV-002030 CAT II

[39] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002010 CAT II, APSC-DV-002020 CAT II, APSC-DV-002030 CAT II

[40] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002010 CAT II, APSC-DV-002020 CAT II, APSC-DV-002030 CAT II

[41] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002010 CAT II, APSC-DV-002020 CAT II, APSC-DV-002030 CAT II

[42] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002010 CAT II, APSC-DV-002020 CAT II, APSC-DV-002030 CAT II

[43] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002010 CAT II, APSC-DV-002020 CAT II, APSC-DV-002030 CAT II

[44] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002010 CAT II, APSC-DV-002020 CAT II, APSC-DV-002030 CAT II

[45] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002010 CAT II, APSC-DV-002020 CAT II, APSC-DV-002030 CAT II

[46] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002010 CAT II, APSC-DV-002020 CAT II, APSC-DV-002030 CAT II

[47] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002010 CAT II, APSC-DV-002020 CAT II, APSC-DV-002030 CAT II

[48] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002010 CAT II, APSC-DV-002020 CAT II, APSC-DV-002030 CAT II

[49] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002010 CAT II, APSC-DV-002020 CAT II, APSC-DV-002030 CAT II

[50] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-000590 CAT II, APSC-DV-002010 CAT II, APSC-DV-002020 CAT II, APSC-DV-002030 CAT II, APSC-DV-002290 CAT II

[51] Standards Mapping - Security Technical Implementation Guide Version 6.1 APSC-DV-000590 CAT II, APSC-DV-002010 CAT II, APSC-DV-002020 CAT II, APSC-DV-002030 CAT II, APSC-DV-002290 CAT II

desc.structural.objc.weak_cryptographic_hash_null_pbe_salt

Abstract

Una sal null (None) puede poner en riesgo la seguridad del sistema de una forma que no es fácil de resolver.

Explanation

Nunca es una buena idea utilizar sal null (None). El uso de sal null no solo facilita enormemente que puedan adivinarse los valores de hash, sino que además dificulta enormemente la solución del problema. Una vez que el código está en producción, no es fácil modificar la sal. Si los usuarios malintencionados descubren que los valores con hash tienen sal null, pueden calcular "tablas arco iris" para la aplicación y determinar más fácilmente los valores con hash.

Ejemplo 1: El código siguiente utiliza sal null (None):


import hashlib, binascii
from django.utils.crypto import pbkdf2

def register(request):
  password = request.GET['password']
  username = request.GET['username']
  dk = pbkdf2(password, None, 100000)
  hash = binascii.hexlify(dk)
  store(username, hash)
...