CVE-2021-40353

Name: CVE-2021-40353
Creator: NVD / NIST
Published: 2021-09-01T01:15:07.027+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 2.88%

Last modified Jun 17, 2026

CVE-2021-40353 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. A SQL injection vulnerability exists in version 8.0 of openSIS when MySQL or MariaDB is used as the application database. An attacker can then issue the SQL command through the index.php USERNAME parameter. EPSS estimates a 2.88% chance of exploitation in the next 30 days.

Description

A SQL injection vulnerability exists in version 8.0 of openSIS when MySQL or MariaDB is used as the application database. An attacker can then issue the SQL command through the index.php USERNAME parameter. NOTE: this issue may exist because of an incomplete fix for CVE-2020-6637.

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

2.88%

85.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-89

Affected Software

Vendor	Product	Versions
Os4ed	Opensis	8.0

References

https://github.com/5qu1n7/CVE-2021-40353Exploit, Third Party Advisory
https://www.opensis.com/download/englishProduct
https://github.com/5qu1n7/CVE-2021-40353Exploit, Third Party Advisory
https://www.opensis.com/download/englishProduct

Timeline

Published: Sep 1, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-40353?

How severe is CVE-2021-40353?

CVE-2021-40353 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 2.88% probability of exploitation in the next 30 days.

How do I fix CVE-2021-40353?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-40353?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST