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Vulnerability record · CVE-2021-42338 · published 19 November 2021

CVE-2021-42338: 4mosan gcb doctor improper authorization vulnerability

4mosan · Gcb Doctor

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.

9.8 CVSS 3.1 Critical EPSS 5.8% · top 7.1% CWE-285 · Improper authorizationCWE-287 · Improper authentication
9.8CVSS 3.1 base score, v2 10.0
5.8%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
2References
17 Jun 2026Last modified by NVD

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.

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

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

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

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.8CVE-2021-441594mosan gcb doctor unrestricted file upload vulnerability4MOSAn GCB Doctor’s file upload function has improper user privilege control. A remote attacker can upload arbitrary files including webshell files w…EPSS 3.4%8.8CVE-2026-58704Android Cellular Modem improper authorization allows adjacent privilege escalationAndroid's Cellular Modem component contains a logic error that bypasses permission checks, allowing an attacker within radio/adjacent range to escala…KEVEPSS 0.59%analysed9.8CVE-2021-28799QNAP HBS 3 improper authorization allows remote loginQNAP Hybrid Backup Sync 3 (HBS 3) contains an improper authorization flaw that lets remote attackers log in to the NAS device. The issue affects mult…KEVEPSS 78%analysed

Source: NIST National Vulnerability Database (record CVE-2021-42338), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.