What is CVE-2021-43657?

CVE-2021-43657 is a medium-severity vulnerability in Simple Client Management System Project, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2022-12-22.

How severe is CVE-2021-43657?

Medium severity. CVSS v3 base score is 5.4 out of 10.

Is CVE-2021-43657 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

XSS in Simple Client Management System Project

CVE-2021-43657

A Stored Cross-site scripting (XSS) vulnerability via MAster.php in Sourcecodetester Simple Client Management System (SCMS) 1.0 allows remote attackers to inject arbitrary web script or HTML via the vulnerable input fields.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2022-12-22 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.007 (51.9th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 52nd percentile — 51.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: 0.000

Affected products

Simple Client Management System Project — versions 1.0

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

Public proof-of-concept exploits

c0n5n3d/CVE-2021-43657

References

github.com/c0n5n3d/CVE-2021-43657/blob/main/Info.txt (Third Party Advisory)

Frequently asked questions

What is CVE-2021-43657?: CVE-2021-43657 is a medium-severity vulnerability in Simple Client Management System Project, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2022-12-22.
How severe is CVE-2021-43657?: Medium severity. CVSS v3 base score is 5.4 out of 10.
Is CVE-2021-43657 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.