CVE-2021-42338

Name: CVE-2021-42338
Creator: NVD / NIST
Published: 2021-11-19T09:15:06.683+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 5.63%

Last modified Jun 17, 2026

CVE-2021-42338 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. 4MOSAn GCB Doctor’s login page has improper validation of Cookie, which allows an unauthenticated remote attacker to bypass authentication by code injection in cookie, and arbitrarily manipulate the system or interrupt services by upload and execution of arbitrary files.. EPSS estimates a 5.63% chance of exploitation in the next 30 days.

Description

4MOSAn GCB Doctor’s login page has improper validation of Cookie, which allows an unauthenticated remote attacker to bypass authentication by code injection in cookie, and arbitrarily manipulate the system or interrupt services by upload and execution of arbitrary files.

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

5.63%

92.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
4mosan	Gcb Doctor	<= 20210708

References

https://www.twcert.org.tw/tw/cp-132-5313-45bde-1.htmlThird Party Advisory
https://www.twcert.org.tw/tw/cp-132-5313-45bde-1.htmlThird Party Advisory

Timeline

Published: Nov 19, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-42338?

How severe is CVE-2021-42338?

CVE-2021-42338 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 5.63% probability of exploitation in the next 30 days.

How do I fix CVE-2021-42338?

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-2021-42338?

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

Scan your code now

Source: NVD / NIST