1.6.1 Ensure system wide crypto policy is not set to legacy

Information

When a system-wide policy is set up, the default behavior of applications will be to follow the policy. Applications will be unable to use algorithms and protocols that do not meet the policy, unless you explicitly request the application to do so.

The system-wide crypto-policies followed by the crypto core components allow consistently deprecating and disabling algorithms system-wide.

The LEGACY This policy ensures maximum compatibility with legacy systems at the cost of being less secure. It allows the TLS 1.2, and TLS 1.3 protocols, as well as IKEv2 and SSH2. DSA is not allowed, while RSA and Diffie-Hellman parameters are accepted if no less than 2048 bits. This policy provides at least 80-bit security.

The LEGACY system-wide crypto policy includes support for outdated and weakened algorithms to ensure maximum compatibility with Red Hat Enterprise Linux 6 and earlier; it is less secure due to an increased attack surface.

These legacy protocols and algorithms can make the system vulnerable to attacks, including those listed in RFC 7457

Solution

Run the following command to change the system-wide crypto policy

# update-crypto-policies --set <CRYPTO POLICY>

Example:

# update-crypto-policies --set DEFAULT

Run the following to make the updated system-wide crypto policy active

# update-crypto-policies

Impact:

Environments that require compatibility with older insecure protocols may require the use of the less secure LEGACY policy level.

See Also

https://workbench.cisecurity.org/benchmarks/24009

Item Details

Category: ACCESS CONTROL, IDENTIFICATION AND AUTHENTICATION, SYSTEM AND COMMUNICATIONS PROTECTION

References: 800-53|AC-17(2), 800-53|IA-5, 800-53|IA-5(1), 800-53|SC-8, 800-53|SC-8(1), CSCv7|14.4

Plugin: Unix

Control ID: 9808e69c68a3554b00b53a1e9412c0950a8251038a3471be7daf2cc253eb6b3a