Froxlor is a server administration panel. In versions 2.3.10 and earlier, the customer data-export (DataDump) cron fails to validate intermediate path components of the export destination: FroxlorFileDir::makeCorrectDir() contains an off-by-one in its path-component walk that skips the first segment below the customer home directory, and the guard in ExportCron.php checks only the final component with is_link(). An authenticated customer whose account has the export feature enabled can schedule an export into a genuine subdirectory of their own webspace, then replace an intermediate path component with a symlink before the root-owned cron runs. The crons chown -R then recursively changes ownership of the linked directory tree — for example /etc — to the customers UID, yielding host root and cross-tenant compromise. Exploitation is deterministic and requires no race. This is an incomplete fix of GHSA-75h4-… The issue is fixed in Froxlor 2.3.12.
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.
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