Weak Cipher Suites Supported

Weak Cipher Suites Supported

Risk: low

Description

This vulnerability indicates that the server supports one or more weak cipher suites. Weak cipher suites are cryptographic algorithms that are considered insecure due to known vulnerabilities or insufficient key lengths.

Weak cipher suites may include: - RC4 - 3DES - Ciphers using MD5 for message authentication - NULL ciphers (no encryption) - EXPORT grade ciphers - DES (Data Encryption Standard) - Anonymous Diffie-Hellman (ADH) or Anonymous Elliptic Curve Diffie-Hellman (AECDH)

These weak cipher suites can lead to various security risks, including:

1. Insufficient encryption strength
2. Vulnerability to known attacks (e.g., BEAST, POODLE, FREAK)
3. Lack of forward secrecy
4. Man-in-the-Middle (MitM) attacks
5. Downgrade attacks forcing the use of weaker ciphers

Example Scenario: An attacker could exploit a weak cipher suite like RC4 to decrypt sensitive information transmitted over an encrypted connection. This could lead to the exposure of login credentials, session tokens, or other confidential data.

Supporting these weak cipher suites also violates various security standards and best practices, potentially impacting compliance with regulations such as PCI DSS, HIPAA, and GDPR.

Recommendation

To address the risks associated with weak cipher suites, consider implementing the following recommendations:

1. Disable Weak Cipher Suites:
2. Remove support for all weak cipher suites, including RC4, 3DES, NULL ciphers, EXPORT grade ciphers, and those using MD5.

3. Disable anonymous key exchange methods (ADH, AECDH).

4. Enable Strong Cipher Suites:

5. Use strong cipher suites that support Perfect Forward Secrecy (PFS).
6. Prefer ECDHE or DHE for key exchange.
7. Use AES-GCM or ChaCha20-Poly1305 for encryption.

8. Ensure message authentication uses SHA-256 or better.

9. Prioritize Cipher Suites:

10. Order cipher suites to prefer the strongest and most secure options.

11. Follow recommendations from reputable sources like Mozilla's SSL Configuration Generator.

12. Implement Secure TLS Configuration:

13. Use TLS 1.2 or TLS 1.3 (preferred).
14. Disable TLS compression to prevent CRIME attacks.

15. Enable OCSP stapling for efficient certificate validation.

16. Implement HTTP Strict Transport Security (HSTS):

17. Use HSTS to ensure clients always connect using HTTPS, preventing downgrade attacks.

Links

• NIST Guidelines for TLS Implementations
• OWASP Transport Layer Protection Cheat Sheet
• SSL Labs: SSL and TLS Deployment Best Practices

Standards

• SOC2_CONTROLS:
  • CC_6_7
  • CC_7_1
• CCPA:
  • CCPA_1798_150
• GDPR:
  • ART_32
• PCI_STANDARDS:
  • REQ_2_3
  • REQ_4_1
  • REQ_6_5