Microsoft Office 365 ProPlus/2019 Outlook Message information disclosure

Summaryinfo

A vulnerability was found in Microsoft Office 365 ProPlus/2019. It has been declared as problematic. The affected element is an unknown function of the component Outlook Message Handler. Executing a manipulation can lead to information disclosure. This vulnerability appears as CVE-2018-8579. The attack may be performed from remote. There is no available exploit. It is advisable to implement a patch to correct this issue.

Detailsinfo

A vulnerability classified as problematic was found in Microsoft Office 365 ProPlus/2019 (Office Suite Software). This vulnerability affects some unknown processing of the component Outlook Message Handler. The manipulation with an unknown input leads to a information disclosure vulnerability. The CWE definition for the vulnerability is CWE-200. The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. As an impact it is known to affect confidentiality. CVE summarizes:

An information disclosure vulnerability exists when attaching files to Outlook messages, aka "Microsoft Outlook Information Disclosure Vulnerability." This affects Office 365 ProPlus, Microsoft Office. This CVE ID is unique from CVE-2018-8558.

The bug was discovered 11/13/2018. The weakness was presented 11/13/2018 with Microsoft as confirmed security update guide (Website). The advisory is shared for download at portal.msrc.microsoft.com. The public release was coordinated in cooperation with the vendor. This vulnerability was named CVE-2018-8579 since 03/14/2018. The attack can be initiated remotely. Required for exploitation is a single authentication. Successful exploitation requires user interaction by the victim. There are neither technical details nor an exploit publicly available. The MITRE ATT&CK project declares the attack technique as T1592. The advisory points out:

An information disclosure vulnerability exists when attaching files to Outlook messages. This vulnerability could potentially allow users to share attached files such that they are accessible by anonymous users where they should be restricted to specific users.

The commercial vulnerability scanner Qualys is able to test this issue with plugin 110325 (Microsoft Office and Microsoft Office Services and Web Apps Security Update November 2018).

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

The vulnerability is also documented in the vulnerability database at SecurityFocus (BID 105828†). See VDB-126715, VDB-126716, VDB-126717 and VDB-126726 for similar entries. Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

• Office Suite Software

Vendor

• Microsoft

Name

• Office

Version

• 365 ProPlus
• 2019

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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