#VU53112 Out-of-bounds read in Microsoft products - CVE-2021-31174

Vulnerability identifier: #VU53112

Vulnerability risk: Low

CVSSv4.0: 5.4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:P/U:Clear]

CVE-ID: CVE-2021-31174

CWE-ID: CWE-125

Exploitation vector: Local

Exploit availability: Yes

Vulnerable software:
Microsoft Office
Client/Desktop applications / Office applications
Microsoft Excel
Client/Desktop applications / Office applications
Office Online Server
Server applications / Other server solutions
Microsoft Office Web Apps Server
Server applications / Application servers

Vendor: Microsoft

Description

The vulnerability allows a local user to gain access to potentially sensitive information.

The vulnerability exists due to a boundary condition in Microsoft Excel. A local user can trigger out-of-bounds read error and read contents of memory on the system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Microsoft Office: 2013 RT - 2013, 2016, 2019

Office Online Server : 2016

Microsoft Excel: 2013 RT Service Pack 1, 2013, 2016

Microsoft Office Web Apps Server: 2013 Service Pack 1

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External links
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31174

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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?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.