CVE-2021-21935Public exploitNetwork attack vector

Database disclosure via host filter SQL injection

Published Dec 22, 2021 · Updated Aug 3, 2024

SQL injection in the device_list page of Advantech R-SeeNet 2.4.16 and earlier allows remote authenticated users to read database data. The page URL-decodes host_alt_filter2, embeds the escaped value in a SQL fragment, and passes it to a stored procedure that concatenates and prepares the fragment without parameter binding. Any authenticated account can reach the flaw, and cross-site request forgery can supply the request; the demonstrated consequence is limited to confidentiality.

CVSS severity7.7
High
EPSS probability1.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

SQL injection in the device_list page of Advantech R-SeeNet 2.4.16 and earlier allows remote authenticated users to read database data. The page URL-decodes host_alt_filter2, embeds the escaped value in a SQL fragment, and passes it to a stored procedure that concatenates and prepares the fragment without parameter binding. Any authenticated account can reach the flaw, and cross-site request forgery can supply the request; the demonstrated consequence is limited to confidentiality.

The record

CVE
CVE-2021-21935
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

Compare your product and version with the public record. A matching version still requires validation against your environment.

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

7.7Cisco TalosCVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
4.0NIST NVDAV:N/AC:L/Au:S/C:P/I:N/A:N
6.5NIST NVDCVSS: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 exploitPublished

Weakness, pattern, technique

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

Public exploit references

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

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo