Multiple broadband routers may behave as open resolvers


Multiple broadband routers contain an issue where they may behave as open resolvers.

A device that runs as a DNS cache server, which responds to any recursive DNS queries that are received is referred to as an open resolver.
Multiple broadband routers may contain an issue where they may behave as open resolvers.

This issue was confirmed by JPCERT/CC and IPA that it affected multiple developers and was coordinated by JPCERT/CC.
In addition, Yasuhiro Orange Morishita of Japan Registry Services Co., Ltd. (JPRS) reported this vulnerability to JPCERT/CC under the Information Security Early Warning Partnership.
CVSS Severity (What is CVSS?)

CVSS V2 Severity:
Base Metrics 5.0 (Medium) [IPA Score]
  • Access Vector: Network
  • Access Complexity: Low
  • Authentication: None
  • Confidentiality Impact: None
  • Integrity Impact: Partial
  • Availability Impact: None
Affected Products

(Multiple Venders)
  • (Multiple Products)

A wide range of products are affected. For more information, please refer to the References JVN#62507275 "Vendor Status"

The device may be used in a DNS amplification attack and unknowingly become a part of a DDoS attack.

[Apply an Update or Change the Settings]
Apply the appropriate solution (update, patch, settings change, etc.) according to the information provided by the developer
Vendor Information

Internet Initiative Japan Inc. BUFFALO INC. Yamaha Corporation YMIRLINK Inc. THE FURUKAWA ELECTRIC CO., LTD. NEC Corporation
CWE (What is CWE?)

  1. Permissions(CWE-264) [IPA Evaluation]
CVE (What is CVE?)


  1. JVN : JVN#62507275
  2. JPCERT REPORT : DDoS attacks using recursive DNS requests (in Japanese)
  3. US-CERT Technical Cyber Security Alert : Alert (TA13-088A) DNS Amplification Attacks
  4. US-CERT Technical Cyber Security Alert : Alert (TA14-017A) UDP-based Amplification Attacks
  5. JPRS : An unsuitable setup of a DNS server"Open Resolver" (in Japanese)
  6. JPNIC : About Open Resolver (in Japanese)
Revision History

  • [2013/09/19]
      Web page was published
      References : Content was added
      Vendor Information : Content was added