Microsoft Office 365 Apps for Enterprise/2016/2019 Excel memory corruption

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6.6$5k-$25k0.00

A vulnerability, which was classified as critical, has been found in Microsoft Office 365 Apps for Enterprise/2016/2019 (Office Suite Software). This issue affects an unknown functionality of the component Excel. The manipulation with an unknown input leads to a memory corruption vulnerability. Using CWE to declare the problem leads to CWE-119. Impacted is confidentiality, integrity, and availability.

The weakness was shared 10/13/2020 as confirmed security guidance (Website). The advisory is shared at portal.msrc.microsoft.com. The identification of this vulnerability is CVE-2020-16930 since 08/04/2020. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. It demands that the victim is doing some kind of user interaction. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 11/18/2020). The advisory points out:

A remote code execution vulnerability exists in Microsoft Excel software when the software fails to properly handle objects in memory. An attacker who successfully exploited the vulnerability could run arbitrary code in the context of the current user. If the current user is logged on with administrative user rights, an attacker could take control of the affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. Users whose accounts are configured to have fewer user rights on the system could be less impacted than users who operate with administrative user rights. Exploitation of the vulnerability requires that a user open a specially crafted file with an affected version of Microsoft Excel. In an email attack scenario, an attacker could exploit the vulnerability by sending the specially crafted file to the user and convincing the user to open the file. In a web-based attack scenario, an attacker could host a website (or leverage a compromised website that accepts or hosts user-provided content) containing a specially crafted file designed to exploit the vulnerability. An attacker would have no way to force users to visit the website. Instead, an attacker would have to convince users to click a link, typically by way of an enticement in an email or instant message, and then convince them to open the specially crafted file. The security update addresses the vulnerability by correcting how Microsoft Excel handles objects in memory.

It is declared as proof-of-concept.

Applying a patch is able to eliminate this problem. A possible mitigation has been published immediately after the disclosure of the vulnerability.

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VulDB Meta Base Score: 7.3
VulDB Meta Temp Score: 6.6

VulDB Base Score: 6.3
VulDB Temp Score: 5.7
VulDB Vector: 🔒
VulDB Reliability: 🔍

Vendor Base Score (Microsoft): 7.8
Vendor Vector (Microsoft): 🔒

NVD Base Score: 7.8
NVD Vector: 🔒

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VulDB Base Score: 🔒
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VulDB Reliability: 🔍

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Exploitinginfoedit

Class: Memory corruption
CWE: CWE-119
ATT&CK: Unknown

Local: No
Remote: Yes

Availability: 🔒
Status: Proof-of-Concept

Price Prediction: 🔍
Current Price Estimation: 🔒

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Recommended: Patch
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Timelineinfoedit

08/04/2020 CVE assigned
10/13/2020 +70 days Advisory disclosed
10/13/2020 +0 days Countermeasure disclosed
10/14/2020 +0 days VulDB entry created
11/18/2020 +35 days VulDB last update

Sourcesinfoedit

Vendor: https://www.microsoft.com/

Advisory: portal.msrc.microsoft.com
Status: Confirmed

CVE: CVE-2020-16930 (🔒)

Entryinfoedit

Created: 10/14/2020 09:30 AM
Updated: 11/18/2020 10:51 PM
Changes: (14) vulnerability_cvss3_nvd_av vulnerability_cvss3_nvd_ac vulnerability_cvss3_nvd_pr vulnerability_cvss3_nvd_ui vulnerability_cvss3_nvd_s vulnerability_cvss3_nvd_c vulnerability_cvss3_nvd_i vulnerability_cvss3_nvd_a vulnerability_cvss2_nvd_av vulnerability_cvss2_nvd_ac vulnerability_cvss2_nvd_au vulnerability_cvss2_nvd_ci vulnerability_cvss2_nvd_ii vulnerability_cvss2_nvd_ai
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