CVE-2021-31207: medium-severity vulnerability in Microsoft Exchange Server 2013 Cumulative…
Microsoft Exchange Server Security Feature Bypass Vulnerability
Published · Updated
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Patch now. It under exploitation confirmed by CISA, has a working public exploit and 2 threat group(s) use it.
Groups known to exploit this vulnerability (MITRE ATT&CK attribution).
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A security feature in Microsoft Exchange Server can be bypassed, allowing attackers to upload and execute malicious files on the server. This vulnerability undermines the server's built-in protections designed to prevent such attacks.
CWE-434 (Unrestricted File Upload) vulnerability in Microsoft Exchange Server allows authenticated or semi-authenticated attackers to bypass file upload restrictions and execute arbitrary code. The vulnerability requires access to Exchange services but circumvents the validation mechanisms that normally prevent dangerous file uploads.
The full analysis of this CVE is available in Portuguese →
In the same product, most dangerous first.