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Insecure encryption algorithm - Cipher Block Chaining

Description​

The application uses algorithms with insecure cipher block chaining.

Impact​

Exploit cipher process vulnerability and collect sensible information.

Recommendation​

Use algorithms considered cryptographically secure.

Threat​

Unauthorized attacker from adjacent network.

Expected Remediation Time​

⌚ 30 minutes.

Score​

Default score using CVSS 3.1. It may change depending on the context of the vulnerability.

Base​

  • Attack vector: A
  • Attack complexity: H
  • Privileges required: N
  • User interaction: R
  • Scope: U
  • Confidentiality: L
  • Integrity: N
  • Availability: N

Temporal​

  • Exploit code madurity: P
  • Remediation level: X
  • Report confidence: X

Result​

  • Vector string: CVSS:3.1/AV:A/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N/E:P/RL:X/RC:X
  • Score:
    • Base: 2.6
    • Temporal: 2.5
  • Severity:
    • Base: Low
    • Temporal: Low

Code Examples​

Compliant code​

Secure cipher algorithms are defined in the application

http {
  server {
    index: "index.html";
    listen: "localhost:4446 ssl";
    server_name: "localhost";
    ssl_prefer_server_ciphers: "on";
    ssl_ciphers: "TLS_DHE_DSS_WITH_AES_128_GCM_SHA256"";
    ssl_certificate: "cert.crt";
    ssl_certificate_key: "cert.key";
    ssl_protocols: "SSLv3 TLSv1.2";
  }
}

Non compliant code​

CBC algorithms could be forced in feasible time

http {
  server {
    index: "index.html";
    listen: "localhost:4446 ssl";
    server_name: "localhost";
    ssl_prefer_server_ciphers: "on";
    ssl_ciphers: "TLS_RSA_WITH_IDEA_CBC_SHA";
    ssl_certificate: "cert.crt";
    ssl_certificate_key: "cert.key";
    ssl_protocols: "SSLv3 TLSv1 TLSv1.1";
  }
}

Requirements​