CVE-2021-44159 | 4MOSAn GCB Doctor - Unrestricted Upload of File

4MOSAn GCB Doctor’s file upload function has improper user privilege control. A remote attacker can upload arbitrary files including webshell files without authentication and execute arbitrary code in order to perform arbitrary system operations or deny of service attack.

Published: 2021-12-20 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2021-44159 is rated High Risk (71.5/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 4.76%). Core evidence: EPSS rose +1.20% over the last day, indicating growing attacker interest. Mandatory action: High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-44159

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-06-15 3.56% 4.76% +1.20%
2 2025-03-30 5.53% 3.56% -1.96%
3 2025-03-29 5.53%

Full EPSS history (18 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-44159

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
3.9 5.9 [email protected]
10.0 2.0 HIGH
AV:N/AC:L/Au:N/C:C/I:C/A:C Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
10.0 10.0 [email protected]

Weakness enumeration for CVE-2021-44159

Affected software / configurations for CVE-2021-44159

Vendor Product Version Raw CPE
4mosan gcb_doctor < 2021-09-16 cpe:2.3:a:4mosan:gcb_doctor:*:*:*:*:*:*:*:*

References for CVE-2021-44159

cvelogic Threat Intelligence