CVE-2021-26639Network attack vector

Unauthenticated server file disclosure via unvalidated input

Published Aug 17, 2022 · Updated Aug 3, 2024

Improper input validation in WISA Smart Wing CMS before r18715.20211229 allows remote attackers to read all server files without authentication. KrCERT identifies deficient validation of user-controlled values in unspecified CMS functions but does not disclose the functions or request parameters. No login is required, and successful network exploitation exposes arbitrary files stored on the Linux server without a reported write or service-interruption effect.

CVSS severity8.1
High
EPSS probability0.45%
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 WISA Smart Wing CMS before r18715.20211229 allows remote attackers to read all server files without authentication. KrCERT identifies deficient validation of user-controlled values in unspecified CMS functions but does not disclose the functions or request parameters. No login is required, and successful network exploitation exposes arbitrary files stored on the Linux server without a reported write or service-interruption effect.

The record

CVE
CVE-2021-26639
Published
Aug 17, 2022
Updated
Aug 3, 2024
Vendor
WISA
Product
Smart Wing CMS
Classifications
CWE-494, CWE-20, T1005
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 17, 2022CVE 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=unspecified <r18715.20211229

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

WISA · Smart Wing CMSversion=unspecified <r18715.20211229

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
8.1KrCERT/CCCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/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-494Download of Code Without Integrity Check
CWE-20Improper Input Validation
T1005Data from Local System

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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