Copyparty is a portable file server. Prior to 1.20.12, there was a missing permission-check in the shares feature (the shr global-option). This vulnerability only applies when the shares feature is used for the specific purpose of creating a share of just a single file inside a folder or either the FTP or SFTP server is enabled, and also made publicly accessible. Given these conditions, when a user is browsing a share through either FTP or SFTP (not http or https), they can gain read-access to the remaining files inside the shared folder by guessing/bruteforcing the filenames. It was not possible to descend into subdirectories in this manner; only the sibling files were accessible. This vulnerability is similar to CVE-2025-58753 which was previously fixed for HTTP and HTTPS, but not for FTP. The FTPS server did not yet exist at that time. This vulnerability is fixed in 1.20.12.
Weakness
The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Copyparty | 9001 | * | 1.20.12 (excluding) |
Potential Mitigations
- Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) [REF-229] to enforce the roles at the appropriate boundaries.
- Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
- For example, consider using authorization frameworks such as the JAAS Authorization Framework [REF-233] and the OWASP ESAPI Access Control feature [REF-45].
- For web applications, make sure that the access control mechanism is enforced correctly at the server side on every page. Users should not be able to access any unauthorized functionality or information by simply requesting direct access to that page.
- One way to do this is to ensure that all pages containing sensitive information are not cached, and that all such pages restrict access to requests that are accompanied by an active and authenticated session token associated with a user who has the required permissions to access that page.