CVE-2020-27643

The %PROGRAMDATA%1EClient directory in 1E Client 5.0.0.745 and 4.1.0.267 allows remote authenticated users and local users to create and modify files in protected directories (where they would not normally have access to create or modify files) via the creation of a junction point to a system directory. This leads to partial privilege escalation.

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://help.1e.com/display/GI/1E+Security+Advisory-1E+Client+for+Windows%3A+CVE-2020-16268%2C+CVE-2020-27643%2C+CVE-2020-27644%2C+CVE-2020-27645