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Insecure encryption algorithm - SHA1

Description

The server where the application is stored supports insecure ciphers - SHA1.

Impact

Reverse a summary function to find sensitive information.

Recommendation

Use algorithms considered cryptographically secure.

Threat

Unauthorized attacker from internal network executing a MitM.

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: O
  • 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:O/RC:X
  • Score:
    • Base: 2.6
    • Temporal: 2.4
  • Severity:
    • Base: Low
    • Temporal: Low

Code Examples

Compliant code

The server uses a secure encryption algorithm

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

The server uses the insecure SHA1 cipher algorithm

http {
server {
index: "index.html";
listen: "localhost:4446 ssl";
server_name: "localhost";
ssl_prefer_server_ciphers: "on";
ssl_ciphers: "ECDH_ECDSA_WITH_AES_256_CBC_SHA";
ssl_certificate: "cert.crt";
ssl_certificate_key: "cert.key";
ssl_protocols: "SSLv3 TLSv1 TLSv1.1";
}
}

Requirements