Nextcloud Desktop Client prior 3.6.1 code injection

Summaryinfo

A vulnerability, which was classified as critical, was found in Nextcloud Desktop Client. Affected by this vulnerability is an unknown functionality. Such manipulation leads to code injection. This vulnerability is listed as CVE-2022-41882. The attack must be carried out locally. There is no available exploit. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in Nextcloud Desktop Client (Cloud Software). It has been rated as critical. Affected by this issue is some unknown functionality. The manipulation with an unknown input leads to a code injection vulnerability. Using CWE to declare the problem leads to CWE-94. The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment. Impacted is confidentiality, integrity, and availability. CVE summarizes:

The Nextcloud Desktop Client is a tool to synchronize files from Nextcloud Server with your computer. In version 3.6.0, if a user received a malicious file share and has it synced locally or the virtual filesystem enabled and clicked a nc://open/ link it will open the default editor for the file type of the shared file, which on Windows can also sometimes mean that a file depending on the type, e.g. "vbs", is being executed. It is recommended that the Nextcloud Desktop client is upgraded to version 3.6.1. As a workaround, users can block the Nextcloud Desktop client 3.6.0 by setting the `minimum.supported.desktop.version` system config to `3.6.1` on the server, so new files designed to use this attack vector are not downloaded anymore. Already existing files can still be used. Another workaround would be to enforce shares to be accepted by setting the `sharing.force_share_accept` system config to `true` on the server, so new files designed to use this attack vector are not downloaded anymore. Already existing shares can still be abused.

The weakness was presented 11/12/2022 as GHSA-3w86-rm38-8w63. The advisory is shared for download at github.com. This vulnerability is handled as CVE-2022-41882 since 09/30/2022. There are neither technical details nor an exploit publicly available. The MITRE ATT&CK project declares the attack technique as T1059.

Upgrading to version 3.6.1 eliminates this vulnerability. The upgrade is hosted for download at github.com. Applying a patch is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Type

• Cloud Software

Vendor

• Nextcloud

Name

• Desktop Client

License

• open-source

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CPE 2.2info

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