VDB-341633 · CVE-2021-47816 · Exploit 49926

Thecus N4800Eco NAS Server Control Panel User Management os command injection

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
7.2	$0-$5k	0.00

Summaryinfo

A vulnerability was found in Thecus N4800Eco NAS Server Control Panel. It has been classified as critical. The affected element is an unknown function of the component User Management Handler. The manipulation leads to os command injection. This vulnerability is listed as CVE-2021-47816. The attack may be initiated remotely. In addition, an exploit is available.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Thecus N4800Eco NAS Server Control Panel (unknown version). This issue affects an unknown code block of the component User Management Handler. The manipulation with an unknown input leads to a os command injection vulnerability. Using CWE to declare the problem leads to CWE-78. The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

Thecus N4800Eco NAS Server Control Panel contains a command injection vulnerability that allows authenticated attackers to execute arbitrary system commands through user management endpoints. Attackers can inject commands via username and batch user creation parameters to execute shell commands with administrative privileges.

The weakness was presented by Metin Yunus Kandemir as 49926. The advisory is shared at exploit-db.com. The identification of this vulnerability is CVE-2021-47816 since 01/14/2026. The exploitation is known to be easy. The attack may be initiated remotely. Technical details are unknown but a public exploit is available. MITRE ATT&CK project uses the attack technique T1202 for this issue.

The exploit is available at exploit-db.com. It is declared as proof-of-concept.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Vendor

Thecus

Name

N4800Eco NAS Server Control Panel

CPE 2.3info

🔒

CPE 2.2info

🔒

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 7.6
VulDB Meta Temp Score: 7.2

VulDB Base Score: 6.3
VulDB Temp Score: 5.7
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 8.8
CNA Vector (VulnCheck): 🔒

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Os command injection
CWE: CWE-78 / CWE-77 / CWE-74
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Access: Public
Status: Proof-of-Concept
Download: 🔒

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

01/14/2026 CVE reserved
01/16/2026 +2 days Advisory disclosed
01/16/2026 +0 days VulDB entry created
01/16/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: 49926
Researcher: Metin Yunus Kandemir
Status: Not defined

CVE: CVE-2021-47816 (🔒)
GCVE (CVE): GCVE-0-2021-47816
GCVE (VulDB): GCVE-100-341633
scip Labs: https://www.scip.ch/en/?labs.20161013

Entryinfo

Created: 01/16/2026 20:22
Changes: 01/16/2026 20:22 (78)
Complete: 🔍
Cache ID: 216::103