CVE-2021-20715Network attack vector

Arbitrary website redirection via unrestricted custom URL requests

Published Apr 27, 2021 · Updated Aug 3, 2024

Improper access control in Hot Pepper Gourmet App for Android and iOS 4.111.0 and earlier allows remote attackers to open arbitrary websites. Its custom URL scheme accepts requests from any arbitrary app and follows the requested URL without restricting the calling app. A user must interact with the attack, which can direct the device to a phishing site but does not expose data or interrupt service.

CVSS severity4.3
Medium
EPSS probability0.87%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper access control in Hot Pepper Gourmet App for Android and iOS 4.111.0 and earlier allows remote attackers to open arbitrary websites. Its custom URL scheme accepts requests from any arbitrary app and follows the requested URL without restricting the calling app. A user must interact with the attack, which can direct the device to a phishing site but does not expose data or interrupt service.

The record

CVE
CVE-2021-20715
Published
Apr 27, 2021
Updated
Aug 3, 2024
Vendor
Recruit Co., Ltd.
Product
Hot Pepper Gourmet App
Classifications
CWE-284, CWE-862
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 27, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=for Android ver.4.111.0 and earlier, and for iOS ver.4.111.0 and earlier

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Recruit Co., Ltd. · Hot Pepper Gourmet Appversion=for Android ver.4.111.0 and earlier, and for iOS ver.4.111.0 and earlier

Published CVSS scores

4.3NIST NVDAV:N/AC:M/Au:N/C:N/I:P/A:N
4.3JPCERT/CCCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
4.3JPCERT/CCAV:N/AC:M/Au:N/C:N/I:P/A:N
4.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-284Improper Access Control
CWE-862Missing Authorization

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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