Vulnerability identifier: #VU82691

Vulnerability risk: Medium

CVSSv3.1: 4.6 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N/E:U/RL:U/RC:C]

CVE-ID: N/A

CWE-ID: CWE-918

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Microsoft Exchange Server
Server applications / Mail servers

Vendor: Microsoft

Description

The disclosed vulnerability allows a remote user to perform SSRF attacks.

The vulnerability exists due to insufficient validation of user-supplied input within CreateAttachmentFromUr(), DownloadDataFromOfficeMarketPlace(), and DownloadDataFromUri() methods. A remote user can send a specially crafted HTTP request and force the application to initiate requests to arbitrary resources.

Successful exploitation of this vulnerability may allow a remote attacker gain access to sensitive data, located in the local network or send malicious requests to other servers from the vulnerable system.

Mitigation
Cybersecurity Help is currently unaware of any official solution to address this vulnerability.

Vulnerable software versions

Microsoft Exchange Server: 2019 Preview 15.02.0196.000 - 2019 CU13 Oct23SU 15.02.1258.027, 2016 Preview 15.01.0225.016 - 2016 CU23 Oct23SU 15.01.2507.034

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External links
http://www.zerodayinitiative.com/advisories/ZDI-23-1581/
http://www.zerodayinitiative.com/advisories/ZDI-23-1580/
http://www.zerodayinitiative.com/advisories/ZDI-23-1579/

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.