Title

The two files generated by the BIND 9.x server dnssec-keygen program must be group owned by the server administrator account, or deleted, after they have been copied to the key file in the name server. (Cat II impact)

Discussion

To enable zone transfer (requests and responses) through authenticated messages, it is necessary to generate a key for every pair of name servers. The key also can be used for securing other transactions, such as dynamic updates, DNS queries, and responses. The binary key string that is generated by most key generation utilities used with DNSSEC is Base64-encoded. A TSIG is a string used to generate the message authentication hash stored in a TSIG RR and used to authenticate an entire DNS message.

Check Content

If the server is in a classified network, this is Not Applicable. With the assistance of the DNS Administrator, identify all dnssec-keygen key files that reside on the BIND 9.x server. An example dnssec-keygen key file will look like: Kns1.example.com_ns2.example.com.+161+28823.key OR Kns1.example.com_ns2.example.com.+161+28823.private For each key file identified, verify that the key file is group-owned by "root": # ls –la -r-------- 1 root root 77 Jul 1 15:00 Kns1.example.com_ns2.example.com+161+28823.key If the key file(s) are not group owned by root, this is a finding.

Fix Text

Change the group ownership of the keys to the root group. # chgrp root <key_file>.

Additional Identifiers

Rule ID: SV-207574r879887_rule

Vulnerability ID: V-207574

Group Title: SRG-APP-000516-DNS-000086

Expert Comments

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