CVE-2020-11443

The Zoom IT installer for Windows (ZoomInstallerFull.msi) prior to version 4.6.10 deletes files located in %APPDATA%Zoom before installing an updated version of the client. Standard users are able to write to this directory, and can write links to other directories on the machine. As the installer runs with SYSTEM privileges and follows these links, a user can cause the installer to delete files that otherwise cannot be deleted by the user.

Weakness

The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.

Affected Software

Potential Mitigations

• Follow the principle of least privilege when assigning access rights to entities in a software system.
• Denying access to a file can prevent an attacker from replacing that file with a link to a sensitive file. Ensure good compartmentalization in the system to provide protected areas that can be trusted.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/132.html
• https://cwe.mitre.org/data/definitions/17.html
• https://cwe.mitre.org/data/definitions/35.html
• https://cwe.mitre.org/data/definitions/76.html

References

• https://support.zoom.us/hc/en-us/articles/201361953-New-Updates-for-Windows
• https://support.zoom.us/hc/en-us/articles/360043036451
• https://support.zoom.us/hc/en-us/articles/360043036451-Security-CVE-2020-11443