V1R2 changes
F5 BIG-IP TMOS DNS STIG V1R2 (2026-09-30) replaced V1R1 (2024-09-26): 1 check updated. It has 12 checks, against 12 in V1R1.
V1R2 checklistV1R1 checklist Compare V1R1 and V1R2 in STIG Compare
- 0 added
- 0 removed
- 1 updated
Updated fields: Discussion 1
Updated in V1R2 (1)
V-265980CAT IIThe F5 BIG-IP DNS implementation must prohibit recursion on authoritative name servers.Discussion
Discussion
A potential vulnerability of DNS is that an attacker can poison a name server's cache by sending queries that will cause the server to obtain host-to-IP address mappings from bogus name servers that respond with incorrect information. Once a name server has been poisoned, legitimate clients may be directed to nonexistent hosts (which constitutes a denial of service), or worse, hosts that masquerade as legitimate ones to obtain sensitive data or passwords.
To guard against poisoning, name servers authoritative for .mil domains must be separated functionally from name servers that resolve queries on behalf of internal clients. Organizations may achieve this separation by dedicating machines to each function or, if possible, by running two instances of the name server software on the same machine: one for the authoritative function and the other for the resolving function. In this design, each name server process may be bound to a different IP address or network interface to implement the required segregation.
DNSSEC ensures that the answer received when querying for name resolution actually comes from a trusted name server. Since DNSSEC is still far from being globally deployed external to DODDoW, and many resolvers either have not been updated or do not support DNSSEC, maintaining cached zone data separate from authoritative zone data mitigates the gap until all DNS data is validated with DNSSEC.
Since DNS forwarding of queries can be accomplished in some DNS applications without caching locally, DNS forwarding is the method to be used when providing external DNS resolution to internal clients.
How these changes are found
Checks are matched across the two releases by V-number. A check counts as updated when DISA gave it a new rule revision (the r number in its SV-…_rule id) and its title, severity, check text, fix text, discussion, CCIs or other fields changed — the same comparison STIG Compare makes. Added checks are new V-numbers; removed checks are V-numbers V1R2 no longer has.
Comparing other releases, or this one against an older release? Pick any two in STIG Compare.