Reino: Security Features

Segurança de software não é o mesmo que software de segurança. Aqui, estamos interessados em tópicos como autenticação, controle de acesso, confidencialidade, criptografia e gestão de privilégios.

Weak Cryptographic Hash: Null PBE Salt

Abstract

Um salt null (nil) pode comprometer a segurança do sistema de uma maneira difícil de remediar.

Explanation

Nunca é uma boa ideia usar um sal null (nil). Não só usar um sal null facilita determinar os valores de hash significativamente, como também faz com que corrigir o problema seja extremamente difícil. Depois que o código estiver em produção, o sal não poderá ser alterado com facilidade. Se os atacantes descobrirem que os valores estão misturados com um sal null, eles poderão calcular "rainbow tables" para o aplicativo e determinar os valores de hash mais facilmente.

Exemplo 1: O código a seguir usa um sal null (nil):


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

Esse código será executado com êxito, mas qualquer usuário que tiver acesso a ele também terá acesso ao sal null. Depois que o programa é distribuído, provavelmente não há como alterar o sal null. Um funcionário com acesso a essas informações pode usá-las para invadir o 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

Um salt null (None) pode comprometer a segurança do sistema de uma maneira difícil de remediar.

Explanation

Nunca é uma boa ideia usar um sal null (None). Não só usar um sal null facilita determinar os valores de hash significativamente, como também faz com que corrigir o problema seja extremamente difícil. Depois que o código estiver em produção, o sal não poderá ser alterado com facilidade. Se os atacantes descobrirem que os valores estão misturados com um sal null, eles poderão calcular "rainbow tables" para o aplicativo e determinar os valores de hash mais facilmente.

Exemplo 1: O código a seguir usa um 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)
...