CVE-2021-45681Network attack vector

Memory corruption via missing QueryInterface reference increment

Published Dec 26, 2021 · Updated Aug 4, 2024

Memory corruption in derive-com-impl before 0.1.2 allows attackers to create invalid references through generated COM interfaces. The derive_com_impl macro generates IUnknown::QueryInterface without calling IUnknown::AddRef before returning an interface pointer, leaving the reference count too low. When consuming code later calls IUnknown::Release, WMI can drop the interface reference and expose the process to an invalid reference and memory corruption.

CVSS severity7.5
High
EPSS probability1.05%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory corruption in derive-com-impl before 0.1.2 allows attackers to create invalid references through generated COM interfaces. The derive_com_impl macro generates IUnknown::QueryInterface without calling IUnknown::AddRef before returning an interface pointer, leaving the reference count too low. When consuming code later calls IUnknown::Release, WMI can drop the interface reference and expose the process to an invalid reference and memory corruption.

The record

CVE
CVE-2021-45681
Published
Dec 26, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 26, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:N/A:P
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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