CVE-2020-17365

Improper directory permissions in the Hotspot Shield VPN client software for Windows 10.3.0 and earlier may allow an authorized user to potentially enable escalation of privilege via local access. The vulnerability allows a local user to corrupt system files: a local user can create a specially crafted symbolic link to a critical file on the system and overwrite it with privileges of the application.

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://cymptom.com/cve-2020-17365-hotspot-shield-vpn-new-privilege-escalation-vulnerability/2020/10/
• https://www.pango.co/sec31944/