VDB-169486 · CVE-2021-1730 · GCVE-0-2021-1730

Microsoft Exchange Server 2016 CU18/2019 CU7

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.
5.1	$0-$5k	0.00

Summaryinfo

A vulnerability, which was classified as problematic, was found in Microsoft Exchange Server 2016 CU18/2019 CU7. This impacts an unknown function. Executing a manipulation can lead to an unknown weakness. This vulnerability is handled as CVE-2021-1730. The attack can be executed remotely. There is not any exploit available. It is best practice to apply a patch to resolve this issue.

Detailsinfo

A vulnerability was found in Microsoft Exchange Server 2016 CU18/2019 CU7 (Groupware Software). It has been declared as problematic. As an impact it is known to affect confidentiality, and integrity. CVE summarizes:

A spoofing vulnerability exists in Microsoft Exchange Server which could result in an attack that would allow a malicious actor to impersonate the user. This update addresses this vulnerability. To prevent these types of attacks, Microsoft recommends customers to download inline images from different DNSdomains than the rest of OWA. Please see further instructions in the FAQ to put in place this mitigations.

The weakness was released 02/09/2021 as confirmed security guidance (Website). The advisory is available at portal.msrc.microsoft.com. This vulnerability was named CVE-2021-1730. Successful exploitation requires user interaction by the victim. The technical details are unknown and an exploit is not available. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 02/25/2026).

It is declared as proof-of-concept.

Applying a patch is able to eliminate this problem. A possible mitigation has been published immediately after the disclosure of the vulnerability.

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Productinfo

Type

Groupware Software

Vendor

Microsoft

Name

Exchange Server

Version

License

commercial

Website

Vendor: https://www.microsoft.com/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.4
VulDB Meta Temp Score: 5.1

VulDB Base Score: 5.4
VulDB Temp Score: 4.9
VulDB Vector: 🔍
VulDB Reliability: 🔍

Vendor Base Score (Microsoft): 5.4
Vendor Vector (Microsoft): 🔍

NVD Base Score: 5.4
NVD Vector: 🔍

CNA Base Score: 5.4
CNA Vector: 🔍

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: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Unknown
CWE: Unknown
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Proof-of-Concept

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: Patch
Status: 🔍

Reaction Time: 🔍
0-Day Time: 🔍
Exposure Time: 🔍

Timelineinfo

12/02/2020 🔍
02/09/2021 +69 days 🔍
02/09/2021 +0 days 🔍
02/09/2021 +0 days 🔍
02/25/2026 +1841 days 🔍

Sourcesinfo

Vendor: microsoft.com

Advisory: portal.msrc.microsoft.com
Status: Confirmed

CVE: CVE-2021-1730 (🔍)
GCVE (CVE): GCVE-0-2021-1730
GCVE (VulDB): GCVE-100-169486

Entryinfo

Created: 02/09/2021 21:31
Updated: 02/25/2026 04:53
Changes: 02/09/2021 21:31 (32), 02/09/2021 21:32 (2), 02/09/2021 21:35 (18), 02/26/2021 06:56 (1), 02/25/2026 04:53 (42)
Complete: 🔍
Cache ID: 216::103