Summary

• A vulnerability in ISC BIND could allow an unauthenticated, remote attacker to access sensitive information on a targeted system.
  
  The vulnerability is due to improper security restrictions imposed by the affected software. As a result, unauthorized clients are allowed to send recursive queries to an affected BIND name server. An attacker could exploit this vulnerability by sending a recursive query request to the targeted system. An exploit could allow the attacker to determine which queries the system had previously serviced, which could allow the attacker to access sensitive information about previous queries. In addition, the attacker could send multiple queries to the targeted system, which could cause a limited denial of service (DoS) condition for other authorized clients.
  
  ISC.org has confirmed the vulnerability and released software updates.

Analysis

• To exploit this vulnerability, an attacker must send a recursive query request to the targeted system, making exploitation more difficult in environments that restrict network access from untrusted sources.

Safeguards

• Administrators are advised to apply the appropriate updates.
  
  Administrators are advised to allow only trusted users to have network access.
  
  Administrators are advised to run both firewall and antivirus applications to minimize the potential of inbound and outbound threats.
  
  Administrators may consider using IP-based access control lists (ACLs) to allow only trusted systems to access the affected systems.
  
  Administrators can help protect affected systems from external attacks by using a solid firewall strategy.
  
  Administrators are advised to monitor affected systems.

Vendor Announcements

• ISC.org has released a security advisory at the following link: AA-01616

Fixed Software

• ISC.org has released an advance version of the patch, which is available upon request from security-officer@isc.org. The patch will also be applied to future releases of BIND, such as versions 9.9.13, 9.10.8, 9.11.4, and 9.12.2.

Revision History

• Version	Description	Section	Date
  1	Initial public release.	—	2018-June-13

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Affected Products

• The security vulnerability applies to the following combinations of products.
  
  

  Primary Products
  Internet Systems Consortium (ISC)	BIND	9.12.0 (Base) | 9.12.1 (Base, -P2) | 9.9.12 (Base, -S1) | 9.10.7 (Base, -S1) | 9.11.3 (Base, -S1, -S2) | 9.13.0 (Base)

  Associated Products