How severe is CVE-2021-45681?

No CVSS score has been assigned to CVE-2021-45681 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2021-45681?

CVE-2021-45681 affects the following packages: derive-com-impl (crates.io). Ecosystems affected: crates.io.

How do I fix CVE-2021-45681?

Update derive-com-impl to 0.1.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-45681 is resolved across your whole dependency graph.

How do I detect CVE-2021-45681 in my crates.io dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for derive-com-impl, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2021-45681 if there is no patch (or I can't update yet)?

Constrain what reaches the vulnerable code: limit the size and shape of untrusted input, isolate the affected component in a sandboxed or least-privileged process, and enable the platform's memory-safety mitigations (ASLR, stack protector, hardened allocator) so an out-of-bounds access is more likely to fail closed than to be exploitable.

Is CVE-2021-45681 actively exploited in the wild?

No public exploit code has been indexed for CVE-2021-45681 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2021-45681?

CVE-2021-45681 has an EPSS (Exploit Prediction Scoring System) score of 1.1%, placing it in the 63th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2021-45681?

CVE-2021-45681 is classified as Out-of-bounds Write (CWE-787). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2021-45681 published, and has it been updated?

CVE-2021-45681 was published on June 16, 2022 and was last updated on November 8, 2023. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🦀 crates.io

Not in CISA KEV

CVE-2021-45681 — derive-com-impl

Fix: Connicpu/com-impl@9803f31

CVE-2021-45681 is a Out-of-bounds Write vulnerability in derive-com-impl. A fix is available for derive-com-impl — see the affected versions and patch details below.

QueryInterface should call AddRef before returning pointer

Also known asGHSA-w4cc-pc2h-whcjRUSTSEC-2021-0083

Published

Jun 16, 2022

Updated

Nov 8, 2023

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 12, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

1.1%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs63th percentile — riskier than 63% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

🦀derive-com-impl

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.

Description

Affected version of this crate, which is a required dependency in com-impl, provides a faulty implementation of the IUnknown::QueryInterface method.

QueryInterface implementation must call IUnknown::AddRef before returning the pointer, as describe in this documentation: https://docs.microsoft.com/en-us/windows/win32/api/unknwn/nf-unknwn-iunknown-queryinterface(refiid_void)

As it is not incrementing the refcount as expected, the following calls to IUnknown::Release method will cause WMI to drop reference to the interface, and can lead to invalid reference.

This is documented in https://docs.microsoft.com/en-us/windows/win32/learnwin32/managing-the-lifetime-of-an-object#reference-counting

There is no simple workaround, as you can't know how many time QueryInterface will be called. The only way to quick fix this is to use the macro expanded version of the code and modify the QueryInterface method to add the AddRef call yourself.

The issue was corrected in commit 9803f31fbd1717d482d848f041044d061fca6da7.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🦀crates.io	`derive-com-impl`	all versions	0.1.2`cargo update -p derive-com-impl --precise 0.1.2`

Affected Products

1 product · 1 configurations

Application

derive-com-implderive-com-impl_project

< 0.1.2

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for derive-com-impl, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update derive-com-impl to 0.1.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-45681 is resolved across your whole dependency graph.
Workarounds
Constrain what reaches the vulnerable code: limit the size and shape of untrusted input, isolate the affected component in a sandboxed or least-privileged process, and enable the platform's memory-safety mitigations (ASLR, stack protector, hardened allocator) so an out-of-bounds access is more likely to fail closed than to be exploitable.

Frequently Asked Questions

Affected version of this crate, which is a required dependency in com-impl, provides a faulty implementation of the `IUnknown::QueryInterface` method. `QueryInterface` implementation must call `IUnknown::AddRef` before returning the pointer, as describe in this documentation: <https://docs.microsoft.com/en-us/windows/win32/api/unknwn/nf-unknwn-iunknown-queryinterface(refiid_void)> As it is not incrementing the refcount as expected, the following calls to `IUnknown::Release` method will cause WMI to drop reference to the interface, and can lead to invalid reference. This is documented in <

O3 Security · Impact-Aware SCA

Is CVE-2021-45681 in your dependencies?

Find it across crates.io, including transitive dependencies.

Scan my dependencies How O3 SCA works