Cybozu Mailwise vulnerable to information disclosure


Cybozu Mailwise contains an information disclosure vulnerability in the page where CGI environment variables are displayed.
Cookie that contains session information has httponly attribute, and the Cookie value cannot be obtained by JavaScript code. However, Cookie values can be obtained in the page where CGI environment variables are displayed. Therefore, session information may be disclosed if the contents of this page is read in some way.

Masato Kinugawa reported this vulnerability to Cybozu, Inc., and Cybozu, Inc. reported this vulnerability to JPCERT/CC to notify users of its solution through JVN. JPCERT/CC and Cybozu, Inc. coordinated under the Information Security Early Warning Partnership.
CVSS Severity (What is CVSS?)

CVSS V3 Severity:
Base Metrics 6.5 (Medium) [IPA Score]
  • Attack Vector: Network
  • Attack Complexity: Low
  • Privileges Required: None
  • User Interaction: Required
  • Scope: Unchanged
  • Confidentiality Impact: High
  • Integrity Impact: None
  • Availability Impact: None
CVSS V2 Severity:
Base Metrics 2.6 (Low) [IPA Score]
  • Access Vector: Network
  • Access Complexity: High
  • Authentication: None
  • Confidentiality Impact: Partial
  • Integrity Impact: None
  • Availability Impact: None
Affected Products

Cybozu, Inc.
  • Cybozu Mailwise version 5.0.0 through 5.3.2


An unauthenticated remote attacker may obtain session information of a user.

[Update the Software]
Update to the latest version according to the information provided by the developer.
Vendor Information

Cybozu, Inc.
CWE (What is CWE?)

  1. Information Exposure(CWE-200) [IPA Evaluation]
CVE (What is CVE?)

  1. CVE-2016-4843

  1. JVN : JVN#03052683
  2. National Vulnerability Database (NVD) : CVE-2016-4843
Revision History

  • [2016/08/16]
      Web page was published
      References : Content was added