Microsoft Windows up to Server 2019 Background Intelligent Transfer Service unrestricted upload

Summaryinfo

A vulnerability was found in Microsoft Windows and classified as critical. This affects an unknown part of the component Background Intelligent Transfer Service. Such manipulation leads to unrestricted upload. This vulnerability is documented as CVE-2020-1255. The attack can be executed remotely. There is not any exploit available. It is advisable to implement a patch to correct this issue.

Detailsinfo

A vulnerability was found in Microsoft Windows (Operating System). It has been rated as critical. Affected by this issue is an unknown code of the component Background Intelligent Transfer Service. The manipulation with an unknown input leads to a unrestricted upload vulnerability. Using CWE to declare the problem leads to CWE-434. The product allows the attacker to upload or transfer files of dangerous types that can be automatically processed within the product's environment. Impacted is confidentiality, integrity, and availability. CVE summarizes:

An elevation of privilege vulnerability exists when the Windows Background Intelligent Transfer Service (BITS) IIS module improperly handles uploaded content, aka 'Windows Background Intelligent Transfer Service Elevation of Privilege Vulnerability'.

The weakness was released 06/09/2020 as confirmed security update guide (Website). The advisory is shared for download at portal.msrc.microsoft.com. The public release was coordinated with the vendor. This vulnerability is handled as CVE-2020-1255. The exploitation is known to be difficult. The attack may be launched remotely. A simple authentication is needed for exploitation. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 06/10/2020). The MITRE ATT&CK project declares the attack technique as T1608.002. The advisory points out:

An elevation of privilege vulnerability exists when the Windows Background Intelligent Transfer Service (BITS) IIS module improperly handles uploaded content. An attacker who successfully exploited this vulnerability could upload restricted file types to an IIS-hosted folder.

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

Entries connected to this vulnerability are available at VDB-156360, VDB-156359, VDB-156358 and VDB-156357. Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Microsoft

Name

• Windows

Version

• 7 SP1
• 8.1
• 10
• 10 1607
• 10 1709
• 10 1803
• 10 1809
• 10 1903
• 10 1909
• 10 2004
• RT 8.1
• Server 1803
• Server 1903
• Server 1909
• Server 2004
• Server 2008 R2 SP1
• Server 2008 SP2
• Server 2012
• Server 2012 R2
• Server 2016
• Server 2019

License

• commercial

Website

• Vendor: https://www.microsoft.com/
• Product: https://www.microsoft.com/en-us/windows

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Once again VulDB remains the best source for vulnerability data.

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