#VU77225 Improper Authentication in Microsoft SharePoint Server - CVE-2023-29357

Vulnerability identifier: #VU77225

Vulnerability risk: High

CVSSv4.0: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:A/U:Amber]

CVE-ID: CVE-2023-29357

CWE-ID: CWE-287

Exploitation vector: Network

Exploit availability: Yes

Vulnerable software:
Microsoft SharePoint Server
Server applications / Application servers

Vendor: Microsoft

Description

The vulnerability allows a remote attacker to bypass authentication process.

The vulnerability exists due to an error within the ValidateTokenIssuer method. A remote attacker can bypass authentication process and gain unauthorized access to the application.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Microsoft SharePoint Server: 2019

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External links
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2023-29357
https://www.zerodayinitiative.com/advisories/ZDI-23-882/

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

Yes. This vulnerability is being exploited in the wild.