#VU54704 Permissions, Privileges, and Access Controls in Microsoft Exchange Server - CVE-2021-34523

Vulnerability identifier: #VU54704

Vulnerability risk: Low

CVSSv4.0: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:A/U:Clear]

CVE-ID: CVE-2021-34523

CWE-ID: CWE-264

Exploitation vector: Local

Exploit availability: Yes

Vulnerable software:
Microsoft Exchange Server
Server applications / Mail servers

Vendor: Microsoft

Description

The vulnerability allows a remote local to escalate privileges on the system.

The vulnerability exists due to application does not properly impose security restrictions in the Microsoft Exchange Server, which leads to security restrictions bypass and privilege escalation.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Microsoft Exchange Server: 15.00.1497.002

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External links
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34523

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Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

Yes. This vulnerability is being exploited in the wild.