"OfferBox" App uses a hard-coded secret key


"OfferBox" App provided by i-plug inc. uses a hard-coded secret key for JWT (CWE-321).

Yuta Yamate of Rakuten Group, Inc. 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 4.0 (Medium) [IPA Score]
  • Attack Vector: Local
  • Attack Complexity: Low
  • Privileges Required: None
  • User Interaction: None
  • Scope: Unchanged
  • Confidentiality Impact: Low
  • Integrity Impact: None
  • Availability Impact: None
Affected Products

  • OfferBox App for Android 2.0.0 to 2.3.17
  • OfferBox App for iOS 2.1.7 to 2.6.14


The hard-coded secret key for JWT may be retrieved if the application binary is reverse-engineered.

The hard-coded secret key has been revoked by the developer on May 8, 2024 therefore this vulnerability is not exploitable.
The developer has released the following updates which do not contain hard-coded secret keys:

* "OfferBox" App for Android 3.0.0
* "OfferBox" App for iOS 3.0.0
Vendor Information

CWE (What is CWE?)

  1. No Mapping(CWE-Other) [IPA Evaluation]
CVE (What is CVE?)

  1. CVE-2024-32988

  1. JVN : JVN#83405304
Revision History

  • [2024/05/10]
      Web page was published