CVE-2021-25509

Local arbitrary-file overwrite via missing input validation

Published Nov 5, 2021 · Updated Aug 3, 2024

Improper input validation in Samsung Flow before 4.8.5.0 allows local users to overwrite arbitrary files in Windows known folders. Samsung has not published the input source, affected component, or validation error that permits attacker-selected files to replace existing content. Exploitation requires local access to an affected Windows installation and can corrupt files accessible through the application's write context.

CVSS severity7.1
High
EPSS probability0.23%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in Samsung Flow before 4.8.5.0 allows local users to overwrite arbitrary files in Windows known folders. Samsung has not published the input source, affected component, or validation error that permits attacker-selected files to replace existing content. Exploitation requires local access to an affected Windows installation and can corrupt files accessible through the application's write context.

The record

CVE
CVE-2021-25509
Published
Nov 5, 2021
Updated
Aug 3, 2024
Vendor
Samsung Electronics
Product
Samsung Flow
Classifications
CWE-20, T1565.001
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Nov 5, 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=- <4.8.5.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

Samsung Electronics · Samsung Flowversion=- <4.8.5.0

Published CVSS scores

7.1NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
3.6NIST NVDAV:L/AC:L/Au:N/C:N/I:P/A:P
5.9Samsung MobileCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

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)
Vectorlocal
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-20Improper Input Validation
T1565.001Stored Data Manipulation

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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