CVE-2021-21937Network attack vector

Authenticated SQL injection via host_alt_filter

Published Dec 22, 2021 · Updated Aug 3, 2024

SQL injection in Advantech R-SeeNet 2.4.15 allows remote authenticated users to read database data via crafted HTTP requests. The host_alt_filter parameter in the web application is incorporated into SQL without adequate neutralization, allowing attacker-controlled query syntax. Authentication or CSRF reachability is required, and the documented impact is confidential data disclosure without integrity or availability effects.

CVSS severity6.5
Medium
EPSS probability1.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

SQL injection in Advantech R-SeeNet 2.4.15 allows remote authenticated users to read database data via crafted HTTP requests. The host_alt_filter parameter in the web application is incorporated into SQL without adequate neutralization, allowing attacker-controlled query syntax. Authentication or CSRF reachability is required, and the documented impact is confidential data disclosure without integrity or availability effects.

The record

CVE
CVE-2021-21937
Published
Dec 22, 2021
Updated
Aug 3, 2024
Vendor
Advantech
Product
R-SeeNet
Classifications
CWE-89, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 22, 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=Advantech R-SeeNet Advantech R-SeeNet 2.4.15 (30.07.2021)

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Advantech · R-SeeNetversion=Advantech R-SeeNet Advantech R-SeeNet 2.4.15 (30.07.2021)

Published CVSS scores

4.0NVDAV:N/AC:L/Au:S/C:P/I:N/A:N
7.7TalosCVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
6.5NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-89Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')
T1190Exploit Public-Facing Application

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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