STIGQter: STIG Summary: Oracle Linux 6 Security Technical Implementation Guide Version: 2 Release: 3 Benchmark Date: 23 Apr 2021:

The Oracle Linux operating system must be configured so that the SSH daemon is configured to only use Message Authentication Codes (MACs) employing FIPS 140-2 approved cryptographic hash algorithms.

DISA Rule

SV-219958r603346_rule

Vulnerability Number

V-219958

Group Title

SRG-OS-000250

Rule Version

OL6-00-000228

Severity

CAT II

CCI(s)

• CCI-001453 - The information system implements cryptographic mechanisms to protect the integrity of remote access sessions.

Weight

10

Fix Recommendation

Edit the "/etc/ssh/sshd_config" file to uncomment or add the line for the "MACs" keyword and set its value to "hmac-sha2-512, hmac-sha2-256" (this file may be named differently or be in a different location if using a version of SSH that is provided by a third-party vendor):

MACs hmac-sha2-512,hmac-sha2-256

The SSH service must be restarted for changes to take effect.
# sudo service sshd restart

Check Contents

Verify the SSH daemon is configured to only use MACs employing FIPS 140-2-approved hashes.

Note: If OL6-00-000534 is a finding, this is automatically a finding as the system cannot implement FIPS 140-2-approved cryptographic algorithms and hashes.

Check that the SSH daemon is configured to only use MACs employing FIPS 140-2-approved hashes with the following command:

# grep -i macs /etc/ssh/sshd_config
MACs hmac-sha2-512,hmac-sha2-256

If any hashes other than "hmac-sha2-512" or "hmac-sha2-256" are listed, the order differs from the example above, they are missing, or the returned line is commented out, this is a finding.

Vulnerability Number

V-219958

Documentable

False

Rule Version

OL6-00-000228

Severity Override Guidance

Verify the SSH daemon is configured to only use MACs employing FIPS 140-2-approved hashes.

Note: If OL6-00-000534 is a finding, this is automatically a finding as the system cannot implement FIPS 140-2-approved cryptographic algorithms and hashes.

Check that the SSH daemon is configured to only use MACs employing FIPS 140-2-approved hashes with the following command:

# grep -i macs /etc/ssh/sshd_config
MACs hmac-sha2-512,hmac-sha2-256

If any hashes other than "hmac-sha2-512" or "hmac-sha2-256" are listed, the order differs from the example above, they are missing, or the returned line is commented out, this is a finding.

Check Content Reference

M

Target Key

2928

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