A vulnerability exists in the FTP server of the Zyxel AX7501-B0 firmware prior to V5.17(ABPC.3)C0, which processes symbolic links on external storage media. A local authenticated attacker with administrator privileges could abuse this vulnerability to access the root file system by creating a symbolic link on external storage media, such as a USB flash drive, and then logging into the FTP server on a vulnerable device.
The product makes files or directories accessible to unauthorized actors, even though they should not be.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Ax7501-b0_firmware | Zyxel | * | 5.17(abpc.3)c0 (excluding) |
Web servers, FTP servers, and similar servers may store a set of files underneath a “root” directory that is accessible to the server’s users. Applications may store sensitive files underneath this root without also using access control to limit which users may request those files, if any. Alternately, an application might package multiple files or directories into an archive file (e.g., ZIP or tar), but the application might not exclude sensitive files that are underneath those directories. In cloud technologies and containers, this weakness might present itself in the form of misconfigured storage accounts that can be read or written by a public or anonymous user.