cyberstrikeus CIS 6.1 — Hide BIND Version String
Profile Applicability
- Authoritative Name Server Level 1
- Caching Only Name Server Level 1
Description
BIND includes a built-in zone, version.bind which may be queried to get the version of the name server. The version may be set to a value of none, to disable reporting of the version information.
Rationale
Making detailed BIND version information easy to obtain remotely helps attackers automate and target their attacks. The information is not necessary for the health of the server, and should not be disclosed.
Impact
Not specified in the PDF.
Audit Procedure
Use the dig command shown below to query the chaos class TXT record on version.bind. If there is no output from the command, or if a value of No Info or None is returned then the configuration is compliant.
$ dig @ns1.cisecurity.org version.bind chaos txt | grep '^version.bind.' | grep TXT
version.bind. 0 CH TXT "No Info"
$ dig @ns2.cisecurity.org version.bind chaos txt | grep '^version.bind.' | grep TXT
$
Remediation
Add or modify the version option to have a value of none in the BIND global options, as shown below.
options {
version "none";
. . .
}
Default Value
Default value returns the current BIND detailed version.
References
Not specified in the PDF.
CIS Controls
| Controls Version | Control | IG 1 | IG 2 | IG 3 |
|---|---|---|---|---|
| v6 | 9 Limitation and Control of Network Ports, Protocols, and Services | Y | Y | Y |
| v7 | 13.2 Remove Sensitive Data or Systems Not Regularly Accessed by Organization | N | Y | Y |
MITRE ATT&CK Mappings
| Tactic | Technique |
|---|---|
| Reconnaissance | T1592.002 - Gather Victim Host Information: Software |
| Discovery | T1082 - System Information Discovery |
Profile
- Level 1 - Authoritative Name Server
- Level 1 - Caching Only Name Server