VMware ESXi Service Port 5989 improper authentication

CVSS Meta Temp Score
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Current Exploit Price (≈)
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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.
8.0$5k-$25k0.00

Summaryinfo

A vulnerability was found in VMware ESXi. It has been rated as critical. This issue affects some unknown processing of the component Service Port 5989. This manipulation causes improper authentication. This vulnerability appears as CVE-2021-21994. There is no available exploit.

Detailsinfo

A vulnerability classified as critical was found in VMware ESXi (Virtualization Software) (version unknown). Affected by this vulnerability is an unknown function of the component Service Port 5989. The manipulation with an unknown input leads to a improper authentication vulnerability. The CWE definition for the vulnerability is CWE-287. When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. As an impact it is known to affect confidentiality, integrity, and availability.

The weakness was presented 07/14/2021 as VMSA-2021-0014. The advisory is shared at vmware.com. This vulnerability is known as CVE-2021-21994. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 10/31/2025).

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

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Vendor

Name

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.0
VulDB Meta Temp Score: 8.0

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

NVD Base Score: 9.8
NVD Vector: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Improper authentication
CWE: CWE-287
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔍

Timelineinfo

01/04/2021 🔍
07/14/2021 +190 days 🔍
07/14/2021 +0 days 🔍
10/31/2025 +1570 days 🔍

Sourcesinfo

Vendor: vmware.com

Advisory: VMSA-2021-0014
Status: Confirmed

CVE: CVE-2021-21994 (🔍)
GCVE (CVE): GCVE-0-2021-21994
GCVE (VulDB): GCVE-100-178633
scip Labs: https://www.scip.ch/en/?labs.20060413

Entryinfo

Created: 07/14/2021 10:21
Updated: 10/31/2025 13:04
Changes: 07/14/2021 10:21 (37), 07/18/2021 09:18 (2), 07/18/2021 09:23 (18), 10/31/2025 13:04 (15)
Complete: 🔍
Cache ID: 216::103

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

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