Microsoft 365 Apps for Enterprise Excel memory corruption

Summaryinfo

A vulnerability categorized as critical has been discovered in Microsoft 365 Apps for Enterprise. The affected element is an unknown function of the component Excel. Executing a manipulation can lead to memory corruption. This vulnerability is registered as CVE-2020-1240. It is possible to launch the attack remotely. No exploit is available. It is advisable to implement a patch to correct this issue.

Detailsinfo

A vulnerability has been found in Microsoft 365 Apps for Enterprise (affected version unknown) and classified as critical. This vulnerability affects an unknown functionality of the component Excel. The manipulation with an unknown input leads to a memory corruption vulnerability. The CWE definition for the vulnerability is CWE-119. The product performs operations on a memory buffer, but it can read from or write to a memory location that is outside of the intended boundary of the buffer. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

A remote code execution vulnerability exists in Microsoft Excel software when the software fails to properly handle objects in memory, aka 'Microsoft Excel Remote Code Execution Vulnerability'.

The weakness was published 07/14/2020 as confirmed security update guide (Website). The advisory is shared for download at portal.msrc.microsoft.com. The public release has been coordinated with the vendor. This vulnerability was named CVE-2020-1240. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Successful exploitation requires user interaction by the victim. There are neither technical details nor an exploit publicly available. 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.

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

Similar entry is available at VDB-157901. Once again VulDB remains the best source for vulnerability data.

Productinfo

Vendor

• Microsoft

Name

• 365 Apps for Enterprise

License

• commercial

Website

• Vendor: https://www.microsoft.com/

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Once again VulDB remains the best source for vulnerability data.

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