CVE-2021-20791

Unauthorized file exchange via improper boundary access

Published Sep 17, 2021 · Updated Aug 3, 2024

Improper access control in RevoWorks Browser 2.1.230 and earlier allows local users to exchange files across its isolation boundary. Access controls between the local and isolated environments improperly govern drives, folders, files, browser settings, and registry data. Local low-privileged access is required; unauthorized files can cross the boundary and browser settings can be altered, without reported service interruption.

CVSS severity5.2
Medium
EPSS probability0.84%
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 RevoWorks Browser 2.1.230 and earlier allows local users to exchange files across its isolation boundary. Access controls between the local and isolated environments improperly govern drives, folders, files, browser settings, and registry data. Local low-privileged access is required; unauthorized files can cross the boundary and browser settings can be altered, without reported service interruption.

The record

CVE
CVE-2021-20791
Published
Sep 17, 2021
Updated
Aug 3, 2024
Vendor
J's Communications Co., Ltd.
Product
RevoWorks Browser
Classifications
CWE-284
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 17, 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=2.1.230 and earlier

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

J's Communications Co., Ltd. · RevoWorks Browserversion=2.1.230 and earlier

Published CVSS scores

3.2JPCERT/CC and IPAAV:L/AC:L/Au:S/C:P/I:P/A:N
5.2JPCERT/CC and IPACVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:L/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.

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No observations available

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

Weakness, pattern, technique

CWE-284Improper Access Control

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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