CVE-2021-33766highunder attack

CVE-2021-33766: high-severity vulnerability in Microsoft Exchange Server 2013 Cumulative…

Microsoft Exchange Server Information Disclosure Vulnerability

Published · Updated

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100Vexday Risk Score

Patch now. It under exploitation confirmed by CISA and has a working public exploit.

ssvc Actcvss 7.3epss 98%
from disclosure to weapon48 days
Published on NVDJul 14
1st PoC+48d
CISA KEV+188d
Action required by CISAfederal deadline: 2022-02-01

Apply updates per vendor instructions.

In short

A security flaw in Microsoft Exchange Server allows attackers to read sensitive information like emails and calendar data without proper authentication. This happens through a weakness in how the server handles certain requests.

Technical detail

This vulnerability permits unauthenticated attackers to disclose sensitive information stored on Exchange Server instances through an improper input validation flaw in the server's request handling mechanism. The attack requires network access to the affected Exchange service and can result in unauthorized access to mailbox contents, calendar data, and other confidential information without requiring valid credentials.

Summary generated and translated by AI from the official description.

The full analysis of this CVE is available in Portuguese →

Microsoft Exchange Server Information Disclosure Vulnerability
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L/E:U/RL:O/RC:C
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