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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