Tonec Internet Download Manager up to 6.42 Build 63 on Windows Kernel Driver idmwfp.sys access control

Summaryinfo

A vulnerability was found in Tonec Internet Download Manager up to 6.42 Build 63 on Windows. It has been rated as critical. This affects an unknown function of the file idmwfp.sys of the component Kernel Driver. This manipulation causes access control. This vulnerability is handled as CVE-2026-90493. It is possible to launch the attack on the local host. Additionally, an exploit exists. The vendor was contacted early about this disclosure but did not respond in any way.

Detailsinfo

A vulnerability was found in Tonec Internet Download Manager up to 6.42 Build 63 on Windows. It has been declared as critical. Affected by this vulnerability is an unknown function of the file idmwfp.sys of the component Kernel Driver. The manipulation with an unknown input leads to a access control vulnerability. The CWE definition for the vulnerability is CWE-284. The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor. As an impact it is known to affect confidentiality, integrity, and availability.

The weakness was released as not defined advisory. The advisory is shared at github.com. This vulnerability is known as CVE-2026-90493. The exploitation appears to be easy. An attack has to be approached locally. Technical details and also a public exploit are known. MITRE ATT&CK project uses the attack technique T1068 for this issue. Internet Download Manager for Windows up to and including 6.42 Build 63 installs idmwfp.sys, a Windows kernel driver that exposes the \\.\IDMWFP device interface to authenticated local users. The device object is created with an access control descriptor equivalent to D:P(A;;GA;;;AU), granting Authenticated Users generic access to the driver. The driver's IOCTL 0x12C028 handler accepts registry-operation subcommands 0x0C through 0x0F and processes caller-controlled registry paths and values. These handlers do not authenticate the caller, do not enforce the caller's registry permissions, and do not restrict operations to IDM-owned registry namespaces. A low-privileged local authenticated user can therefore read, create, modify, and delete arbitrary registry values under HKLM and HKU through the kernel driver. This includes registry configuration consumed by privileged Windows services and drivers and enables Local Privilege Escalation, high-privilege persistence, unauthorized system configuration disclosure or modification, and compromise of system confidentiality, integrity, and availability. Exploitation requires local access, low privileges, and no user interaction. A public proof of concept is available.

It is possible to download the exploit at github.com. It is declared as proof-of-concept. The vendor was contacted early about this disclosure but did not respond in any way.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-76938). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Vendor

• Tonec

Name

• Internet Download Manager

Version

• 6.42 Build 63

CPE 2.3info

• 🔒

CPE 2.2info

• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Submitinfo

Accepted

• Submit #891910: Tonec Inc. / Internet Download Manager Corp. Internet Download Manager (IDM) for Windows <= 6.42 Build 63 Exposed IOCTL with Insufficient Access Control (by KnCRJNET)

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Discussion