Executive brief
Internet Download Manager is a Windows download utility installed on millions of computers. The application includes a kernel driver (idmwfp.sys) that grants low-privileged local users direct access to read and modify system registry settings normally restricted to administrators. An attacker with basic user access can exploit this to gain administrator privileges, install persistent malware, or disable security controls.
Technical details
The vulnerability is an improper access control flaw in the idmwfp.sys kernel driver installed by Internet Download Manager. The driver exposes the \.\IDMWFP device interface to all authenticated local users and implements IOCTL 0x12C028 handlers that accept registry-operation subcommands (0x0C–0x0F) without validating caller identity, caller registry permissions, or restricting operations to IDM-owned namespaces. A low-privileged local authenticated user can invoke these IOCTLs with arbitrary registry paths to read, create, modify, or delete registry values under HKLM and HKU, including settings consumed by privileged Windows services. The attack requires only local network or physical access and valid user credentials; no user interaction or elevation prompts are needed. Public proof-of-concept code is available, and patches have not been provided by the vendor.
Affected products
- Tonec Internet Download Manager up to 6.42 Build 63
Timeline
- 2026-09-13: disclosed
- other: Public proof-of-concept available; vendor non-responsive