CyberSecBulletin
CVE-2026-90493NVD status: Deferred

Internet Download Manager: Incorrect Privilege Assignment

CVE-2026-90493 is a high-severity incorrect privilege assignment vulnerability in Internet Download Manager from Tonec, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. Affected Internet Download Manager versions: 6.42 Build 63. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.15% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of Internet Download Manager you run against the affected versions below, and install the vendor's latest release.

Affected products and versions

VendorProductAffected versionsFixed in
TonecInternet Download Manager6.42 Build 63Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
ChangedThe attack can reach beyond the vulnerable component into other systems.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H. Scored by CNA (vuldb.com).

Scoring systemScoreSeverityScored by
CVSS 4.08.5HighCNA (vuldb.com)
CVSS 3.18.8HighCNA (vuldb.com)
CVSS 2.06.8MediumCNA (vuldb.com)

Official description

A vulnerability was detected in Tonec Internet Download Manager up to 6.42 Build 63 on Windows. The impacted element is an unknown function of the file idmwfp.sys of the component Kernel Driver. The manipulation results in improper access controls. Attacking locally is a requirement. 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. The exploit is now public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Incorrect Privilege Assignment

A product incorrectly assigns a privilege to a particular actor, creating an unintended sphere of control for that actor.

How developers prevent this class of flaw

  • Very carefully manage the setting, management, and handling of privileges. Explicitly manage trust zones in the software.
  • Run your code using the lowest privileges that are required to accomplish the necessary tasks. If possible, create isolated accounts with limited privileges that are only used for a single task. That way, a successful attack will not immediately give the attacker access to the rest of the software or its environment. For example, database applications rarely need to run as the database administrator, especially in day-to-day operations.

More Incorrect Privilege Assignment vulnerabilities (CWE-266)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Internet Download Manager

All Internet Download Manager vulnerabilities

Recent Incorrect Privilege Assignment vulnerabilities

Spotted an error? Tell us.