Cybozu Garoon access restriction bypass vulnerability


Single sign-on function of Cybozu Garoon provided by Cybozu, Inc. contains a restriction bypass vulnerability (CWE-284).

Kanta Nishitani 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 7.5 (High) [IPA Score]
  • Attack Vector: Network
  • Attack Complexity: Low
  • Privileges Required: None
  • User Interaction: None
  • Scope: Unchanged
  • Confidentiality Impact: High
  • Integrity Impact: None
  • Availability Impact: None
CVSS V2 Severity:
Base Metrics 5.0 (Medium) [IPA Score]
  • Access Vector: Network
  • Access Complexity: Low
  • Authentication: None
  • Confidentiality Impact: Partial
  • Integrity Impact: None
  • Availability Impact: None
Affected Products

Cybozu, Inc.
  • Cybozu Garoon 3.0.0 to 4.10.0


An attacker who can access the product may bypass authentication of Single sign-on function and view the information which is available only for sign-on users.

[Apply the Patch]
Apply the patch according to the information provided by the developer.

[Updated on 2019 April 22]
[Update the Software]
Update to the latest version according to the information provided by the developer.
According to developer, this vulnerability was addressed in Cybozu Garoon 4.10.1.
Vendor Information

Cybozu, Inc.
CWE (What is CWE?)

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

  1. CVE-2018-16178

  1. JVN : JVN#25385698
  2. National Vulnerability Database (NVD) : CVE-2018-16178
Revision History

  • [2018/12/10]
      Web page was published
  • [2019/04/22]
      Solution was modified
  • [2019/08/27]
      References : Content was added