Optical BB unit E-WMTA2.3 vulnerable to cross-site request forgery


Optical BB unit E-WMTA2.3 provided by SoftBank contains a cross-site request forgery vulnerability (CWE-352).

Hiroki Nishino reported this vulnerability to IPA.
JPCERT/CC coordinated with the developer under Information Security Early Warning Partnership.
CVSS Severity (What is CVSS?)

CVSS V3 Severity:
Base Metrics 5.4 (Medium) [IPA Score]
  • Attack Vector: Network
  • Attack Complexity: Low
  • Privileges Required: None
  • User Interaction: Required
  • Scope: Unchanged
  • Confidentiality Impact: None
  • Integrity Impact: Low
  • Availability Impact: Low
CVSS V2 Severity:
Base Metrics 4.0 (Medium) [IPA Score]
  • Access Vector: Network
  • Access Complexity: High
  • Authentication: None
  • Confidentiality Impact: None
  • Integrity Impact: Partial
  • Availability Impact: Partial
Affected Products

  • Optical BB unit E-WMTA2.3


If a user views a malicious page while logged in, unintended operations may be performed.

[Update the firmware]
According to the developer, the fixed firmware for this vulnerability has been released in December 2020, and the update is applied automatically.
Vendor Information

CWE (What is CWE?)

  1. Cross-Site Request Forgery(CWE-352) [IPA Evaluation]
CVE (What is CVE?)

  1. CVE-2021-20783

  1. JVN : JVN#34364599
Revision History

  • [2021/07/14]
      Web page was published